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MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (measuring physical variables of any kind by conversion into electric variables, see Note (4) following the title of class G01; measuring diffusion of ions in an electric field, e.g. electrophoresis, electro-osmosis G01N; investigating non-electric or non-magnetic properties of materials by using electric or magnetic methods G01N; indicating correct tuning of resonant circuits H03J 3/12; monitoring electronic pulse counters H03K 21/40; monitoring operation of communication systems H04).
Definition statement
This subclass/group covers:

Measuring electric variables or properties.

Measuring electric variables directly, e.g. electromechanical instruments (see Glossary of terms) where the measured electric variables directly effect the indication of the measured value.

Measuring electric variables by derivation from other electric variables, i.e. arrangements (see Glossary of terms) involving circuitry to obtain an indication of a measured value by deriving, calculating or otherwise processing electric variables, e.g. by comparison with another value.

Measuring or investigating electric properties of materials.

Electric testing of analogue or digital electric devices, apparatus or networks, or measuring their characteristics.

Indicating presence or sign of current or voltage.

The following technical subjects are therefore covered, the list being non-exhaustive:

Measuring time integral of electric power or current (i.e. Energy), e.g. Of consumption

Displaying electric variables or waveforms

Measuring currents or voltages or for indicating presence or sign thereof

Measuring electric power or power factor

Measuring time integral of electric power or current, e.g. By electronic methods

Measuring frequencies (of electric signals); measuring and analysing frequency spectra (of electric signals)

Measuring phase angle between a voltage and a current or between voltages or currents

Measuring resistance, reactance, impedance, or electric characteristics derived therefrom

Testing electric properties of apparatus, e.g. Discharge tubes, amplifiers, transistors, integrated circuits

Locating electric faults

Electrical testing characterised by what is being tested not provided for elsewhere

Testing for digital signal parameters (delay, skew, signal level) and characterization of device performance by use of test patterns; test apparatus or integrated test circuits therefor; methods for test pattern generation

Details, testing or calibrating of g01r related instruments or arrangements

Measuring magnetic variables or properties

Measuring magnetic variables.

Measuring or investigating magnetic properties of materials.

The following technical subjects are therefore covered, the list being non-exhaustive:

Measuring direction or amount of magnetic fields, or measuring characteristics of magnetic materials

Apparatus based on magnetic resonance, e.g. Nmr, mri, epr (i.e. Esr) (see synonyms and keywords) and not specially adapted for a particular application

Details, testing or calibrating of related instruments or arrangements

Relationship between large subject matter areas

Investigating electric variables or properties

This subclass covers measuring or investigating electric properties of materials, whereas measuring or investigating non-electric or non-magnetic properties of materials by the use of electric means or based on electrical variables is covered by e.g. group G01N 27/00.

Investigating magnetic variable or properties

This subclass also covers, under group G01R 33/00, measuring or investigating magnetic properties of materials, whereas measuring or investigating non-magnetic or non-electric properties of materials by the use of magnetic means is covered by group G01N 27/72.

In particular, group G01R 33/20 covers measuring magnetic variables/properties by using magnetic resonance, e.g. NMR, EPR or other spin effects, whereas investigating or analysing materials by using such spin effects is covered by group G01N 24/00.

References relevant to classification in this subclass
This subclass/group does not cover:

Examples of places where the subject matter of this class is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Medical diagnosis by electric means, e.g. by measuring bioelectric currents or voltages, or the impedance of a part of the body
Medical diagnosis by means of magnetic fields, e.g. involving ESR, NMR or MRI
Monitoring electric consumption of electrically-propelled vehicles
Ascertaining earth's true or magnetic north for navigation or surveying purposes
Magnetic resonance gyrometers
Investigating or analysing materials by using NMR, EPR (i.e. ESR) or other spin effects
Investigating non-electric or non-magnetic properties of materials by the use of electric means
Investigating non-electric or non-magnetic properties of materials by the use of magnetic means
Electric prospecting or detecting
Measuring direction or magnitude of the magnetic earth's field; Magnetic prospecting or detecting, e.g. well logging involving NMR
Measuring atmospheric potential differences, e.g. due to electrical charges in clouds
Indicating correct tuning of resonant circuits

Places in relation to which this subclass is residual:

Electrical testing characterised by what is being tested not provided for elsewhere
Electric testing of control systems
Testing computers during standby operation or idle time
Testing of switches in structural association with the switches themselves
Testing discharge tubes during manufacture
Testing or measuring semiconductors or solid state devices during manufacture or treatment
H01L21/66
Accumulators with integrated arrangements for testing condition
Testing of A/D or D/A conversion
Testing line transmission systems
Testing arrangements of data switching networks
Testing arrangements of telephone substation equipments
Testing of television systems or details thereof
Testing arrangements of loudspeakers, microphones or similar electromechanical transducers
Testing lamps structurally associated with light source circuit arrangements for detecting lamp failure
Informative references
Attention is drawn to the following places, which may be of interest for search:
Electrotherapy
Magnetotherapy
Measuring not specially adapted for a specific variable
Measuring not specially adapted for a specific variable
Tariff metering apparatus
Measuring temperature based on the use of electric elements directly sensitive to heat
Measuring temperature based on the use of magnetic elements directly sensitive to heat
Systems for regulating electric variables
Systems for regulating magnetic variables
Image data processing or generation
Image data processing or generation
Monitoring of signal or alarm line circuits, e.g. signalling of line faults
Superconducting magnetsMagnets
Electric switches; Emergency protective devices
Cathode-ray tubes
Thermo-electric solid state devices
Thermo-magnetic solid state devices
Devices using galvano-magnetic or similar magnetic effects, e.g. Hall effect
Aerials
Emergency protective circuit arrangements
Circuit arrangements for charging, or depolarising batteries or for supplying loads from batteries
Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing dynamo-electric machines
Generation of oscillations
Modulation
Frequency discriminators; Phase discriminators
Amplifiers
Impedance networks, e.g. resonant circuits; Resonators
Tuning resonant circuits; Selecting resonant circuits
Pulse technique
A/D or D/A conversion
Housings for electric apparatus
Arrangements for monitoring manufacture of assemblages of electric components
Screening of electric apparatus or components against electric fields
Screening of electric apparatus or components against magnetic fields
Special rules of classification within this subclass

Concerning the "measuring of electric variables" part, the following applies when classifying: The most pertinent group is given as an EC. If several groups are equally pertinent (so if it is not clear which EC to allocate), several EC's or an EC and additional Indexing Codes are given.

General remark: G01R (electric part) is a big subclass with many low level subgroups. When classifying at group or subgroup level, care should taken to see to it that the document(s) really concern the measuring of an electric variable and that all higher level (subclass, group, subgroup) definitions are met with.

The scheme was created at a time when electromechanical instruments were common. The groups closely linked to such instruments are rarely used for classifying measuring or testing devices that fall under G01R.

It means what it says; many groups of G01R are not used any more, because the definitions are outdated (contrary to other fields we do not "bend" EC interpretations to fit present days technology.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Measuring properties
can also be interpreted as investigating propertiesRemark: Measuring "properties" is rarely a subject for patenting in G01R.
Instruments or measuring instruments
means electro-mechanical measuring mechanisms Remark: This rule is of little relevance, as electromechanical devices are basically obsolete.
DUT
Device Under Test
Arrangements for measuring
means apparatus, circuits, or methods for measuring
Synonyms and Keywords

In patent documents the following abbreviations are often used:

EPR
Electron paramagnetic resonance
ESR
Electron spin resonance
NMR
Nuclear magnetic resonance
MRI
Magnetic resonance imaging
MRS
Magnetic resonance spectroscopy
NQR
Nuclear quadrupole resonance
Details of instruments or arrangements of the types included in groups G01R 5/00 to G01R 13/00 and G01R 31/00 (constructional details particular to [N: electromechanical] arrangements for measuring the electric consumption G01R 11/02)
General constructional details (details of a kind applicable to measuring arrangements not specially adapted for a specific variable G01D 7/00)
Definition statement
This subclass/group covers:

Structural, tangible details of devices.

References relevant to classification in this group
This subclass/group does not cover:
Constructional details common to different types of electric apparatus
Housings; Supporting members; Arrangements of terminals ("burn-in" aspects G01R 31/286; terminals H01R; terminal strips or boards H02B; housings for electrical apparatus H05K)
Relationship between large subject matter areas

Details concerning arrangements of terminals for the testing of circuits, which do not fit into the definitions of G01R 1/04 and dependent subgroups, are classified in G01R 31/2886. Examples: Contacting devices or procedures without clear mechanical or geometrical features (as defined in the subgroups of G01R 1/04).

[N: Test clips, e.g. for IC`s]
Definition statement
This subclass/group covers:

Test clips, which are contacting devices that clip onto the integrated circuit to be tested.

Measuring probes [N: (plugs, sockets or clips G01R 1/0408; testing of connections G01R 31/04; contacting IC`s for test purposes when probe design is not the essential feature G01R 31/2886; using radiation beam as probe G01R 31/302; end pieces for wires terminating in a probe H01R 11/18)]
Definition statement
This subclass/group covers:

Probes for connecting to electric devices for measuring or testing purposes.

Relationship between large subject matter areas

Connecting devices or methods for the testing of electrical circuits which do not fit into G01R1/067 or a subgroup of G01R 1/067 are classified in G01R 31/2886.

Sockets, and details of sockets such as contacts, for receiving integrated circuits for testing are classified in G01R 1/0433.

[N: Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins]
Definition statement
This subclass/group covers:

Constructional details of individual probe elements or tips.

References relevant to classification in this group
This subclass/group does not cover:
Contact pieces of test sockets
Informative references
Attention is drawn to the following places, which may be of interest for search:
End pieces terminating in a probe
[N: Microprobes, i.e. having dimensions as IC details]
Definition statement
This subclass/group covers:

Geometric details where the dimensions are of microscopic dimensions, corresponding to features of integrated elements.

[N: Material aspects]
Definition statement
This subclass/group covers:

Details related to the material as such (alloy, heat treatment, surface deposit...)

[N: Input circuits therefor]
Definition statement
This subclass/group covers:

Circuits being part of or closely linked to a probe, such as amplifiers, filters or power supplies integrated in a probe.

[N: High frequency probes]
Definition statement
This subclass/group covers:

Probes adapted for the measuring of high frequencies, for example by having low inductance leads, low loss or linear frequency properties.

[N: High voltage probes]
Definition statement
This subclass/group covers:

Probes specially adapted for measuring high voltages.

Multiple probes [N: (G01R 1/06783, G01R 1/06794, G01R 1/071, G01R 1/072 take precedence)]
Definition statement
This subclass/group covers:

Probes having multiple contacting points

[N: arranged on a flexible frame or film]
Definition statement
This subclass/group covers:

Probes mounted on a flexible membrane, such as so called "membrane probes".

[N: with flexible bodies, e.g. buckling beams]
Definition statement
This subclass/group covers:

Probes having long needles, which flex when pressed against the DUT.

References relevant to classification in this group
This subclass/group does not cover:
Probes with spring loaded pogo pins
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:

In this group the following terms (or expressions) are used with the meaning indicated:

DUT
Device under test
[N: with provisions for altering position, number or connection of probe tips; Adapting to differences in pitch]
Definition statement
This subclass/group covers:

Features related to geometrical adaption between probe tips and probe output, e.g. using an adapter board.

[N: manipulating each probe element or tip individually]
Definition statement
This subclass/group covers:

Manipulation of one or more individual probe elements, e.g. the tip part.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Manipulating a single (i.e. single contact) probe.
Manipulating a complete "multi probe"
Screening arrangements against electric or magnetic fields, e.g. against earth`s field [N: (measuring shielding efficiency H05K 9/0069)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Screening of electrical apparatus or components in general
Apparatus or processes specially adapted for the manufacture [N: or maintenance] of measuring instruments, [N: e.g. of probe tips]
Instruments for converting a single current or a single voltage into a mechanical displacement (vibration galvanometers G01R 9/02)
Definition statement
This subclass/group covers:

Instruments classified in this group may be used as indicating instruments for electric or non-electric variables.

Instruments capable of converting two or more currents or voltages into a single mechanical displacement (G01R 9/00 takes precedence)
Definition statement
This subclass/group covers:

Instruments classified in this group may be used as indicating instruments for electric or non-electric variables.

References relevant to classification in this group
This subclass/group does not cover:
Instruments employing mechanical resonance
Instruments employing mechanical resonance
Electromechanical arrangements for measuring time integral of electric power [N: i.e. electric energy] or current, e.g. of consumption ([N: other arrangements for measuring time integral of electric power or current G01R 22/00; Boards, panels, desks for energy meters, H02B 1/03]; monitoring electric consumption of electrically-propelled vehicles B60L 3/00)
Definition statement
This subclass/group covers:

Electromechanical arrangements for measuring time integral of electric power or current such as conventional electromechanical electricity meters, i.e. comprising a rotating disk.

References relevant to classification in this group
This subclass/group does not cover:
Monitoring electric consumption of electrically-propelled vehicles
Tariff metering apparatus, e.g. for measuring gas or water consumption but also for general metering where the type of consumption is not of interest; utility meters
Remote reading of utility meters
Electronic power meters are classified
Electronic electricity (energy) meters
Boards, panels, desks (and parts or accessories therefor) for energy meters
Constructional details (applicable to electric measuring instruments in general G01R 1/00)
Definition statement
This subclass/group covers:

Unless one of the subgroups apply, add-ons, such as electronic counters or optical ports, are seen as "constructional details".

Housings; Supporting racks; Arrangements of terminals
Definition statement
This subclass/group covers:

Housings for electromechanical electricity meters. "Supporting racks" are the internal supports for holding the Ferraris wheels, decade counters, transformers and other internal components of the electromechanical electricity meters. See e.g. US4791362, CH158284.

Relationship between large subject matter areas

Housings which are used only for electronic meters are classified in G01R 22/065.

Supporting, cabinets comprising installation places for electricity meters but also other installation places e.g. for circuit breakers are classified in H02B 1/03.

References relevant to classification in this group
This subclass/group does not cover:
Boards, panels, parts, accessories for energy meters
Casings, cabinets or drawers for electric apparatus
Arrangements for avoiding or indicating fraudulent use [N: (measures against unauthorized operation of bolts, nuts or pins F16B 41/005; security seals G09F 3/03; preventing of tampering with detection circuits in signaling or alarm circuits G08B 29/046)]
Relationship between large subject matter areas

If the arrangement for avoiding or indicating fraudulent use is related to electronic electricity meters the document should be classified in the corresponding subgroups of G01G22/06D3.

Arrangements for indicating or signaling faults (seals G09F 3/03; preventing tampering with detection circuits in signaling or alarm circuits G08B 29/046)
Relationship between large subject matter areas

If the arrangement for indicating or signalling faults is related to electronic electricity meters the document should be classified in the corresponding subgroups of G01G22/06D4.

References relevant to classification in this group
This subclass/group does not cover:
Seals
Preventing tampering with detection circuits in signalling or alarm circuits
Special tariff meters (tariff metering in general G01D 4/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Tariff metering in general
Multi-rate meters (G01R 11/63 takes precedence)
References relevant to classification in this group
This subclass/group does not cover:
Over-consumption meters, e.g. measuring consumption while a predetermined level of power is exceeded
Arrangements for displaying electric variables or waveforms (display by mechanical displacement only G01R 5/00, G01R 7/00, G01R 9/00; recording frequency spectrum G01R 23/18)
Definition statement
This subclass/group covers:

Oscilloscopes and the like for measuring and displaying waveforms.

Relationship between large subject matter areas

If the document is directed to aspects of measuring of current or voltage (e.g. A/D conversion, signal conditioning) the classes G01R 19/2506 and lower take preference.

Modular arrangements for computer based systems (e.g. virtual systems) are classified in G01R 19/2516 (when the document is related to the measuring part).

Display by mechanical displacement only is classified in G01R 5/00, G01R 7/00, G01R 9/00.

Recording frequency spectrum is classified in G01R 23/18

References relevant to classification in this group
This subclass/group does not cover:
Recognising patterns in signals
Control arrangements or circuits for visual indicators common to CRT indicators and other visual indicators (image data processing or generation, in general G06T)
for displaying measured electric variables in digital form ([N: using LCD`s or LED`s G01R 13/40]; counters G06M; analogue/digital conversion in general H03M 1/00)
Definition statement
This subclass/group covers:

All digital oscilloscopes.

Relationship between large subject matter areas

Older type cathode-ray oscilloscopes using digital processors and intermediate A.D. and D.A. converters are classified in G01R 13/345.

If the emphasis is set on the current or voltage measuring part, e.g. signal conditioning, details concerning sampling, digitizing G01R 19/2506 and lower, as well as G01R 19/252, G01R 19/255 and G01R 19/257 take preference.

Modular arrangements for computer based systems are classified in G01R 19/2516.

When the type of the display is of importance, e.g. LCD display G01R 13/403 is used.

References relevant to classification in this group
This subclass/group does not cover:
LCD display of oscilloscopes
Two or three dimensional representation of values
General arrangements for monitoring or analysing measured signals, using A.D. convertersmeasuring current or voltage using digital measurement techniques
Modular arrangements for computer based systems for measuring current or voltage
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cathode-ray oscilloscopes with intermediate digital signal processing (note: older digital oscilloscopes are also partly classified here although they should be classified in G01R 13/02 and lower)
Data acquisition and logging in general
Counters
Analogue/digital conversion in general
[N: in numerical form]
Definition statement
This subclass/group covers:

Systems for displaying a waveform by a table or the like with numerical values. Other characterising values, even single values, of waveforms are also covered here.

Relationship between large subject matter areas

Displaying charts of waveforms are classified in G01R 13/0218 and lower and in G01R 13/029 or in the parent class G01R 13/02.

[for triggering, synchronization]
References relevant to classification in this group
This subclass/group does not cover:
Detection of starting points in a waveform, when the waveform is not displayed
Ultrasonic measurements for analysing materials
Determination of distance by electromagnetic or acoustic wave reflection
[N: for sampling]
Definition statement
This subclass/group covers:

Details of sampling circuits when they are used only in digital oscilloscopes.

Relationship between large subject matter areas

More general details of sampling are classified in G01R 19/2506 and lower. These classes can in cases of interest also be given in parallel.

References relevant to classification in this group
This subclass/group does not cover:
Details of sampling and waveform capturing which are not part of digital oscilloscopes
A.D. converters
[N: Software therefor]
Definition statement
This subclass/group covers:

Software used in digital oscilloscopes and the like.

References relevant to classification in this group
This subclass/group does not cover:
Detection of starting points in a waveform, when the waveform is not displayed
Ultrasonic measurements for analysing materials
Determination of distance by electromagnetic or acoustic wave reflection
Special rules of classification within this group

If the software calculates a trigger event an additional class is given in G01R 13/0254 (although the title thereof relates to circuits). Similarly the other groups of G01R 13/0218 are given in parallel to G01R 13/029.

Cathode-ray oscilloscopes; [N: Oscilloscopes using other screens than CRT's, e.g. LCD's; (control arrangements or circuits for cathode-ray tube indicators G09G 1/00; cathode ray tubes H01J 31/00)]
Definition statement
This subclass/group covers:

Analogue oscilloscopes with cathode-ray screens or oscilloscopes which have an intermediate digital part but which use a traditional cathode-ray screen.

Relationship between large subject matter areas

Digital oscilloscopes are classified in G01R 13/02 and lower. If the type of display is of interest, G01R 13/40 and lower is used, e.g. G01R 13/403 for liquid crystal displays (LCD).

References relevant to classification in this group
This subclass/group does not cover:
Digital oscilloscopes
LCD displays of oscilloscopes
Control arrangements or circuits for cathode-ray tube indicators
Cathode ray tubes
[N: Non-electric appliances, e.g. scales, masks (luminescent screens for CRT provided with permanent marks or references H01J 29/34; optical or photographic arrangements combined with CRT vessels H01J 29/89)]
References relevant to classification in this group
This subclass/group does not cover:
Luminescent screens for CRT provided with permanent marks or references
Optical or photographic arrangements combined with CRT vessels
[N: Using means for generating permanent registrations, e.g. photographs (optical or photographic arrangements combined with CRT vessel H01J 29/89)]
References relevant to classification in this group
This subclass/group does not cover:
Optical or photographic arrangements combined with CRT vessel
[N: Arrangements for obtaining a 3- dimensional representation (stereoscopic T.V. H04N 13/00)]
References relevant to classification in this group
This subclass/group does not cover:
Two or three dimensional representation of measured values in general
Stereoscopic T.V.
Circuits therefor (circuits for generating pulses, e.g. saw-tooth waveforms H03K 3/00)
References relevant to classification in this group
This subclass/group does not cover:
Circuits for generating pulses, e.g. saw-tooth waveforms
Circuits for controlling the intensity of the electron beam [N: or the colour of the display] (brilliance control H01J 29/98)
Definition statement
This subclass/group covers:

Circuits of analogue storage oscilloscopes.

References relevant to classification in this group
This subclass/group does not cover:
Brilliance control in general
Circuits for simultaneous or sequential presentation of more than one variable (electronic switches H03K 17/00)
References relevant to classification in this group
This subclass/group does not cover:
Electronic switches
Circuits for representing a single waveform by sampling, e.g. for very high frequencies (sample and hold arrangements G11C 27/02)
References relevant to classification in this group
This subclass/group does not cover:
Sample and hold arrangements in general
[N: for displaying periodic H.F. signals (G01R 13/345 takes precedence)]
References relevant to classification in this group
This subclass/group does not cover:
For displaying sampled signals by using digital processors by intermediate A.D. and D.A. convertors
[N: for displaying sampled signals by using digital processors by intermediate A.D. and D.A. convertors (control circuits for CRT indicators)]
Definition statement
This subclass/group covers:

Cathode-ray oscilloscopes whereby the intermediary signal processing is performed by a digital processor but the resulting waveform is converted back to an analogue signal to be displayed on the cathode-ray screen.

References relevant to classification in this group
This subclass/group does not cover:
Digital oscilloscopes
[N: using electro-optic elements]
References relevant to classification in this group
This subclass/group does not cover:
Discharge tubes in general
using the steady or oscillatory displacement of a light beam by an electromechanical measuring system (such measuring systems per se G01R 5/00, G01R 7/00, G01R 9/00)
Relationship between large subject matter areas
Such measuring systems per se
using modulation of a light beam otherwise than by mechanical displacement, e.g. by Kerr effect [N: (visual indication of correct tuning H03J 3/14)]
Definition statement
This subclass/group covers:

Documents where the type of the display of the oscilloscope is of interest.

Relationship between large subject matter areas

Cathode ray oscilloscopes are classified in G01R 13/20 and lower. Digital oscilloscopes wherein the type of display is not of importance are classified in G01R 13/02 and lower.

References relevant to classification in this group
This subclass/group does not cover:
Visual indication of correct tuning
[N: using active, i.e. light-emitting display devices, e.g. electroluminescent display (G01R 13/36 and G01R 13/42 take precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Instruments using length of spark discharge e.g. by measuring maximum separation of electrodes to produce spark
[N: using passive display devices, e.g. liquid crystal display or Kerr effect display devices]
Definition statement
This subclass/group covers:

Documents where the type of the display of the oscilloscope is of interest.

Relationship between large subject matter areas

Cathode ray oscilloscopes are classified in G01R 13/20 and lower. Digital oscilloscopes wherein the type of display is not of importance are classified in G01R 13/02 and lower.

[N: for discontinuous display, i.e. display of discrete values (analogue/digital conversion H03M 1/00)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Analogue/digital conversion
[N: representing measured value by a dot or a single line (G01R 13/408 takes precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Two or three dimensional representation of measured values
[N: using a plurality of passive display elements, e.g. liquid crystal or Kerr-effect display elements (G01R 13/408 takes precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Two or three dimensional representation of measured values
Details of measuring arrangements of the types provided for in groups G01R 17/00 to G01R 29/00 and G01R 33/00 to G01R 35/00 (details of instruments G01R 1/00; overload protection arrangements G01R 1/36)
References relevant to classification in this group
This subclass/group does not cover:
Details of instruments
Overload protection arrangements
[N: Circuits for altering the indicating characteristic, e.g. making it non-linear]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Altering a transfer function when measuring not specially adapted for a specific (e.g. electric) variable
Circuits for altering the measuring range
Informative references
Attention is drawn to the following places, which may be of interest for search:
Range change when measuring not specially adapted for a specific (e.g. electric) variable
using capacitive devices [N: (circuits constituting a voltage divider G01R 15/06)]
Definition statement
This subclass/group covers:

Measuring of voltage or through capacitive coupling with the conductor to be measured.

References relevant to classification in this group
This subclass/group does not cover:
Measuring an electric field as such
using inductive devices, e.g. transformers
Definition statement
This subclass/group covers:

Measuring current or voltage using coils or transformers (having interacting windings; the primary winding can be made up by a straight conductor surrounded by the secondary).

References relevant to classification in this group
This subclass/group does not cover:
Measuring a current via the magnetic field, using a coil as sensor
Informative references
Attention is drawn to the following places, which may be of interest for search:
Transformers and inductances as such
using galvano-magnetic devices, e.g. Hall-effect devices, [N: i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices (electromechanical such devices, G01R 5/00, G01R 7/00, G01R 9/00; measuring magnetic fields G01R 33/02 )]
References relevant to classification in this group
This subclass/group does not cover:
Measuring magnetic fields as such, using galvano-magnetic devices
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Galvano magnetic device
Having an interaction between a current and a magnetic field in the device itself
[N: using Hall-effect devices (Hall elements in arrangements for measuring electrical power G01R 21/08)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Hall effect devices as such
[N: using electro-optical modulators, e.g. electro-absorption (probes containing electro-optic elements G01R 1/071)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Measuring an electric field as such, using electro-optical modulation
Measuring arrangements involving comparison with a reference value, e.g. bridge
Arrangements for measuring currents or voltages or for indicating presence or sign thereof (G01R 5/00 takes precedence; [N: voltage measurements using secondary electron emission when testing electronic circuits G01R 31/305]; for measuring bio-electric currents or voltages A61B 5/04)
References relevant to classification in this group
This subclass/group does not cover:
Instruments for converting a single current or a single voltage into a mechanical displacement
[N: Measuring mean values of current or voltage during a given time interval]
Informative references
Attention is drawn to the following places, which may be of interest for search:
When not specially adapted for a specific variable
[N: Circuits for comparing several input signals and for indicating the result of this comparison e.g. equal, different, greater, smaller (comparing pulses or pulse trains according to amplitude)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Logic circuits characterised by logic function
Measuring effective values, i.e. root-mean-square values
Informative references
Attention is drawn to the following places, which may be of interest for search:
Analogue computers for evaluating mean square values.
G07G7/20
Measuring RMS values when not specially adapted for a current or voltage measurement
Measuring peak values [N: or amplitude or envelope] of ac or of pulses
Definition statement
This subclass/group covers:

Measuring of amplitude of periodic voltage or current is also covered.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Peak detectors for pulses.
Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values (circuits with regenerative action, e.g. Schmitt trigger H03K 3/00; threshold switches H03K 17/00)
Definition statement
This subclass/group covers:

Threshold detectors as such, when seen as a measurement circuit (for current or voltage).

Informative references
Attention is drawn to the following places, which may be of interest for search:
Transition or edge detectors for pulses
Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
Informative references
Attention is drawn to the following places, which may be of interest for search:
Zero-crossing detectors for pulses
using digital measurement techniques (arrangements for displaying measured electric variables in digital form G01R 13/02) [N: Analogue/digital conversion H03M]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Analogue/digital conversion
using analogue/digital converters of the type with conversion of voltage or current into frequency and measuring of this frequency
Informative references
Attention is drawn to the following places, which may be of interest for search:
Analog to digital converters as such
using analogue/digital converters of the type with counting of pulses during a period of time proportional to voltage or current, delivered by a pulse generator with fixed frequency
Informative references
Attention is drawn to the following places, which may be of interest for search:
Analogue to digital converters as such
using analogue/digital converters of the type with comparison of different reference values with the value of voltage or current, e.g. using step-by-step method
Informative references
Attention is drawn to the following places, which may be of interest for search:
Analogue to digital converters as such
adapted for measuring in circuits having distributed constants
Definition statement
This subclass/group covers:

Adaptations where the measured signals have wavelengths in the order of magnitude of the circuits present, i.e. high frequencies (theoretically, signals on very long conductors are also covered, but such applications are unusual).

Informative references
Attention is drawn to the following places, which may be of interest for search:
Testing of microwave or radiofrequency circuits
Arrangements for measuring electric power or power factor (G01R 7/12 takes precedence)
Definition statement
This subclass/group covers:

Analogue and digital measurements of power or power factor.

Also measurements of power for high frequency signals.

This group covers additionally the measurement of power when it is an essential aspect of a measurement of electric energy (time integral of power).

Relationship between large subject matter areas

Electronic measurements of energy (time integral of power) is classified in G01R 22/06 when the power measurement therein is not the essential part.

References relevant to classification in this group
This subclass/group does not cover:
Arrangements for monitoring electric power systems
Arrangements for providing remote indication of network conditions
Arrangements for AC mains network controlling
[N: Measuring real or reactive component; Measuring apparent energy (G01R 21/01, G01R 21/02, G01R 21/08, G01R 21/10 and G01R 21/127 take precedence)]
References relevant to classification in this group
This subclass/group does not cover:
In circuits having distributed constants
By thermal methods
By using galvanomagnetic effect devices
By using square-law characteristics of circuit elements
By using pulse modulation
Measurements of real or reactive component or of apparent energy measured by digital technique
[N: Measuring real component]
References relevant to classification in this group
This subclass/group does not cover:
Measurements of real component measured by digital technique
[N: Measuring reactive component]
References relevant to classification in this group
This subclass/group does not cover:
Measurements of reactive component measured by digital technique
[N: Measuring apparent power]
References relevant to classification in this group
This subclass/group does not cover:
Measurements of apparent energy measured by digital technique
[N: Adapted for special tariff measuring (G01R 21/01, G01R 21/02, G01R 21/08, G01R 21/10, G01R 21/1278 and G01R 21/1333 take precedence)]
References relevant to classification in this group
This subclass/group does not cover:
In circuits having distributed constants
By thermal methods
By using galvanomagnetic effect devices
By using square-law characteristics of circuit elements
By using pulse modulation
Digital meters adapted for special tariff measuring
[N: Measuring maximum demand]
Definition statement
This subclass/group covers:

maximum load or demand monitors.

in circuits having distributed constants (G01R 21/04, G01R 21/07, G01R 21/09, G01R 21/12 take precedence)
Definition statement
This subclass/group covers:

Power measurements whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

References relevant to classification in this group
This subclass/group does not cover:
Arrangements for monitoring electric power systems, logging
By thermal methods
By measuring current and voltage
By using galvanomagnetic effect devices
By using square-law characteristics of circuit elements
Arrangements for providing remote indication of network conditions
by thermal methods [N: e.g. calorimetric]
Definition statement
This subclass/group covers:

Power measurements by thermal methods for high frequency signals.

in circuits having distributed constants
Definition statement
This subclass/group covers:

Power measurements by thermal methods whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

by measuring current and voltage (G01R 21/08 to G01R 21/133 take precedence)
References relevant to classification in this group
This subclass/group does not cover:
By using: galvanomagnetic effect devices; square-law characteristics of circuit elements; pulse modulation; digital techniques
in circuits having distributed constants (G01R 21/09 takes precedence)
Definition statement
This subclass/group covers:

Power measurements by using voltage and current measurements whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

References relevant to classification in this group
This subclass/group does not cover:
By using galvanomagnetic effect devices, in circuits having distributed constants
by using galvanomagnetic effect devices, e.g. Hall effect devices (such devices per se H01L; [N: for current measurements only, see G01R 15/20])
References relevant to classification in this group
This subclass/group does not cover:
Galvano-magnetic effect devices, e.g. Hall effect devices, for current measurements only
Hall effect devices per se
in circuits having distributed constants
Definition statement
This subclass/group covers:

Power measurements by using galvano-magnetic effect devices whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

by using square-law characteristics of circuit elements, e.g. diodes, to measure power absorbed by loads of known impedance (G01R 21/02 takes precedence)
Definition statement
This subclass/group covers:

Power measurement for high frequency signals which use such square-law characteristics of circuit elements.

References relevant to classification in this group
This subclass/group does not cover:
By thermal methods
in circuits having distributed constants
Definition statement
This subclass/group covers:

Power measurements by using square-law characteristics of circuit elements whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

by using pulse modulation (G01R 21/133 takes precedence; [N: digital multiplication via delta sigma modulation G06F 7/60])
References relevant to classification in this group
This subclass/group does not cover:
By using digital tecnhique
Digital multiplication via delta sigma modulation
by using digital technique
Definition statement
This subclass/group covers:

Power meters using a digital processor.

Additionally measurements of power in meters for electric energy (time integral of power) when the measurement of power is the essential aspect.

Relationship between large subject matter areas

Digital energy meters (time integral of power) are classified in G01R 22/10 when the power measuring part thereof is not of main importance. However if the power measuring aspect in such digital energy meters is of main interest then it is classified here in G01R 21/133 and lower.

Digital measurements of voltages or currents in electric power systems are classified in G01R 19/2513, e.g. for monitoring the quality of the power signal.

References relevant to classification in this group
This subclass/group does not cover:
Monitoring electric consumption of electrically-propelled vehicles
Electromechanical arrangements for measuring time integral of power or current
Arrangements for monitoring electric power systems by using digital measurement techniques
Electronic energy meters
Digital energy meters
Coin-freed apparatus with meter-controlled dispensing of electricity
Arrangements for providing remote indication of network conditions
Arrangements for AC mains network controlling
[N: Measuring maximum demand]
Definition statement
This subclass/group covers:

Maximum load or maximum demand power meters.

Arrangements for measuring time integral of electric power or current, e.g. by electricity meters (electromechanical arrangements therefor G01R 11/00; monitoring electric consumption of electrically-propelled vehicles B60L 3/00; coin freed devices G07F 15/00)]
Definition statement
This subclass/group covers:

Methods other than electromechanical for measuring time integral of electric power.

Relationship between large subject matter areas

An arrangement for measuring time integral of electric power is classified in group G01R 21/00 if the essential characteristic is the measuring of electric power.

References relevant to classification in this group
This subclass/group does not cover:
Monitoring electric consumption of electrically-propelled vehicles
Electromechanical arrangements for measuring time integral of power or current
Arrangements for measuring electric power
Coin freed devices
Arrangements for providing remote indication of network conditions
Arrangements for AC mains network controlling
by electronic methods
Definition statement
This subclass/group covers:

Electronic methods for measuring time integral of power, whereby analogue or digital techniques can be used.

[N: related to remote communication]
Definition statement
This subclass/group covers:

Aspects of electricity meters for remote reading in the sense that the meter has special adaptations which go beyond standard communication systems.

Relationship between large subject matter areas

Managing power networks by using distributed power monitors and using standard communication protocols is classified in H02J 13/00.

If the communication protocol as such is of interest the document is classified in H04B 1/00.

References relevant to classification in this group
This subclass/group does not cover:
Remote reading of utility meters
Telemetrie
Circuit arrangements for providing remote indication of network conditions
Data transmission systems
[N: related to mechanical aspects]
Definition statement
This subclass/group covers:

Housings specially adapted (or used only) for electronic electricity meters.

This group also covers adaptations to the housing of an electronic electricity meter in order to add a certain functionality and whereby mechanical aspects of this adaptation are of importance.

References relevant to classification in this group
This subclass/group does not cover:
Cabinets which also can be used for electricity meters Distribution boards or subassemblies, which may comprise installation places for electricity meters but which also have installation places for other units such as circuit breakers etc.
Casings, cabinets or drawers for electric apparatus
Arrangements for avoiding or indication of fraudulent use in electromechanical electricity meters
Security arrangements for protecting computers against unauthorized activity
[N: Arrangements for avoiding or indicating fraudulent use]
using analogue techniques
Definition statement
This subclass/group covers:

Electricity meters which are based on an analogue electronic circuit.

References relevant to classification in this group
This subclass/group does not cover:
Electromechanical electricity meters
using digital techniques
Definition statement
This subclass/group covers:

Digital arrangements for measuring time integral of electric power, such as electricity meters, whereby the digital processing is of importance.

Relationship between large subject matter areas

Details relating to measuring of electric power are classified in G01R 21/133.

Digital measurements of voltages or currents in electric power systems are classified in G01R 19/2513, e.g. for monitoring the quality of the power signal.

Arrangements for measuring frequencies; Arrangements for analysing frequency spectra (frequency discriminators H03D; [N: high frequency probes G01R 1/06772])
Definition statement
This subclass/group covers:

Arrangements for measuring frequencies of electrical signals as such.

arrangements for analysing frequency spectra of electric signals if the analysis thereof comprises aspects of the determination of frequency components.

Relationship between large subject matter areas

The mere use of known frequency measurement or analysis methods or devices is classified in the appropriate application class, such as G01N 27/00 or G01N 22/00.

References relevant to classification in this group
This subclass/group does not cover:
Frequency measurement of non electric signals. Frequency analysis, e.g. analytical spectometry.Algorithms for spectral analysis as such.
Frequency discriminators
Investigating materials by use of microwaves
Investigating materials by use of electric or magnetic means
Demodulation of frequency modulated signals
Digital receivers
Receivers for broadcast information
[N: Circuits for comparing several input signals and for indicating the result of this comparison, e.g. equal, different, greater, smaller (comparing phase or frequency of 2 mutually independent oscillations in demodulators)]
References relevant to classification in this group
This subclass/group does not cover:
By heterodyning; by beat-frequency comparison
Indicating that frequency of pulses is either above or below a predetermined value or within or outside a predetermined range of values, by making use of non-linear or digital elements
Circuits for comparing the frequencies of two mutually independent oscillations
Arrangements for measuring frequency, e.g. pulse repetition rate [N: (using vibrating reeds G01R 9/04)] Arrangements for measuring period of current or voltage (measuring short-time intervals G04F)
References relevant to classification in this group
This subclass/group does not cover:
Arrangements for measuring frequency using vibrating reeds
Measuring short-time intervals
adapted for measuring in circuits having distributed constants
Definition statement
This subclass/group covers:

Measurements of frequencies whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

using response of circuits tuned on resonance, e.g. grid-drip meter
Definition statement
This subclass/group covers:

Measuring instruments using a resonant frequency, e.g. an oscillator output energy which changes in the vicinity of a resonant circuit which is tuned to the frequency the oscillator generates.

using analogue integrators, e.g. capacitors establishing a mean value by balance of input signals and defined discharge signals or leakage (radiation-measuring instruments in which pulses generated by a radiation detector are integrated G01T 1/15)
References relevant to classification in this group
This subclass/group does not cover:
Radiation-measuring instruments in which pulses generated by a radiation detector are integrated
by heterodyning; by beat-frequency comparison (generation of oscillations by beating unmodulated signals of different frequencies H03B 21/00)
Definition statement
This subclass/group covers:

Frequency measurements wherein signals of different frequencies are combined in order to generate intermediate frequencies / interference signals which are used for the measurement (heterodyning).

Also frequency measurements based on a comparison to a signal of a similar reference frequency.

References relevant to classification in this group
This subclass/group does not cover:
Generation of oscillations by beating unmodulated signals of different frequencies
[N: by heterodyning or by beat-frequency comparison with the harmonic of an oscillator]
Definition statement
This subclass/group covers:

Frequency measurements wherein the reference signal is a harmonic signal of an (adjustable) oscillator.

[N: giving an indication of the number of times this occurs, i.e. multi-channel analysers (for pulse characteristics)]
Definition statement
This subclass/group covers:

Also digital determinations of a single frequency.

Spectrum analysis; Fourier analysis [N: (computing with Fourier series or Walsh functions G06F 17/14, G06G 7/19; spectral data processing)]
Definition statement
This subclass/group covers:

Spectrum-analysers and the like, e.g. digital spectrum analysers using algorithms performed on a micro-processor whereby the electric signal measurement apparatus, and not only a pure mathematical algorithm, is of interest.

Relationship between large subject matter areas

Digital spectrum analysers are normally classified in this class unless one or more of the subgroups are relevant. The subgroups are however directed to devices for spectrum analysis which were not based on algorithm performed on microprocessors.

Determination of a single frequency is classified in G01R 23/15. Frequency selective measuring of voltage level is classified in G01R 19/04.

References relevant to classification in this group
This subclass/group does not cover:
Investigating materials by use of microwaves
Investigating materials by use of electric or magnetic means
Computing with Fourier series or Walsh functions
Feature extraction from signals
Demodulation of frequency modulated signals
Receivers for broadcast information
Digital receivers
Synonyms and Keywords

In patent documents the following abbreviations are often used:

FFT
Fast Fourier Transformation
DFT
Discrete Fourier Transformation
adapted for measuring in circuits having distributed constants
Definition statement
This subclass/group covers:

Spectrum analysis for frequencies whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

References relevant to classification in this group
This subclass/group does not cover:
For measuring a single frequency in circuits having distributed constants
with digital filters
Relationship between large subject matter areas

Digital spectrum analysers using an algorithm performed on a microprocessor are classified in G01R 23/16.

Wobbulating devices similar to swept panoramic receivers (panoramic receivers per se H03J 7/32)
References relevant to classification in this group
This subclass/group does not cover:
Panoramic receivers per se
with provision for recording frequency spectrum
Definition statement
This subclass/group covers:

For example devices which such provisions for recording in order to display the result on a screen.

Measurement of non-linear distortion, [N: e.g. harmonics or noise, (G01R 31/31708 takes precedence; noise figure G01R 29/26)]
Definition statement
This subclass/group covers:

The measurement of non-linear distortion by frequency analysis.

References relevant to classification in this group
This subclass/group does not cover:
Measurement of phase shift of four pole networks
Measurement of noise figure, signal-to-noise ratio or jitter (phase noise)
Testing of individual semiconductor devices
Testing (or characterizing) of electronic circuits
Analysis of signal quality
Arrangements for measuring phase angle between a voltage and a current, or between voltages or currents (measuring power factor G01R 21/00; measuring position of individual pulses in a pulse train G01R 29/02; phase discriminators H03D)
Definition statement
This subclass/group covers:

Phase measurements of electrical signals as such.

References relevant to classification in this group
This subclass/group does not cover:
Measuring power factor
Measuring position of individual pulses in a pulse train
Circuits for comparing the phase of two mutually independent oscillations
Phase locked loops

Examples of places where the subject matter of this subgroup is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Investigating or analysing materials by the use of electric, electro-chemical, or magnetic means
Automatic control of frequency or phase; Synchronisation
Phase-modulated carrier systems, i.e. using phase-shift keying
[N: Circuits for comparing several input signals and for indicating the result of this comparison e.g. equal, different, greater, smaller, or for passing one of the input signals as output signal]
References relevant to classification in this group
This subclass/group does not cover:
Phase locked loops
in circuits having distributed constants
Definition statement
This subclass/group covers:

Phase measurements whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

by counting of standard pulses (measuring time intervals G04F)
References relevant to classification in this group
This subclass/group does not cover:
Measuring position of individual pulses in a pulse train
Measuring time intervals
Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom [N: (measuring super-conductive properties G01R 33/1238)]
Definition statement
This subclass/group covers:

Measurements of resistance, reactance or impedance as such whereby the measurement comprises aspects which are not generally known in the art.

Relationship between large subject matter areas

The use of such measurements is classified in the appropriate classes for the application.

References relevant to classification in this group
This subclass/group does not cover:
Measuring contours by electric means
Sensors using a capacitive element
Flow measurements
Temperature measurements
Pressure/ Force measurements
Analysing materials by investigating resistance
Analysing materials by investigating capacitance
Acceleration measurements
Measuring super-conductive properties
Sensors using a resistive element
Sensors using an inductive element
Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant (by measuring phase angle only G01R 25/00)
Definition statement
This subclass/group covers:

Measurements of complex impedance.

Groups G01R 27/02 to G01R 27/22 cover variables that directly or indirectly can be measured over two poles of a component or a Thevenin two-pole equivalent. Subgroup G01R 27/26 also covers other techniques, e.g. using electro-magnetic waves or network analyzers.

Measurements of capacitance only is classified in G01R 27/2605.

Measurements of inductance only is classified in G01R 27/2611.

References relevant to classification in this group
This subclass/group does not cover:
Measuring phase angle only
[N: Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters]
References relevant to classification in this group
This subclass/group does not cover:
Measuring resistance to earth
Testing of leakage or ground faults
Testing dielectric strength of cable insulation
in circuits having distributed constants, [N: e.g. having very long conductors or involving high frequencies]
Definition statement
This subclass/group covers:

Impedance measurements whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies.

Measuring reflection coefficients; Measuring standing-wave ratio
References relevant to classification in this group
This subclass/group does not cover:
Measuring dielectric loss, e.g. loss angle
Measuring resistance by measuring current or voltage obtained from a reference source (G01R 27/16, G01R 27/20, G01R 27/22 take precedence)
References relevant to classification in this group
This subclass/group does not cover:
Measuring impedance of element or network through which a current is passing from another source
Measuring earth resistance; Measuring contact resistance
Measuring resistance of fluids
Measuring resistance to earth, [N: i.e. line to ground]
Definition statement
This subclass/group covers:

Measurements of resistance between a high voltage line and ground when current from another source is passing the high voltage line.

References relevant to classification in this group
This subclass/group does not cover:
Measurement of isolation resistance
Testing of leakage or ground faults
Measuring earth resistance; Measuring contact resistance, [N: e.g.] of earth connections, e.g. plates
Definition statement
This subclass/group covers:

Measurements of resistance of lines which are intended for grounding, such as the resistance of the PE line or of the resistance of the earth as such.

References relevant to classification in this group
This subclass/group does not cover:
Testing of continuity
Testing of connections
[N: Measuring contact resistance of connections, e.g. of earth connections]
Definition statement
This subclass/group covers:

Contact resistance measurements, e.g. of earth connections, but also of other connections, e.g. between terminal blades and sockets.

References relevant to classification in this group
This subclass/group does not cover:
Testing of continuity
Testing of connections
Measuring resistance of fluids (measuring vessels, electrodes therefor G01N 27/07)
References relevant to classification in this group
This subclass/group does not cover:
Measuring vessels, electrodes for the Measuring resistance of fluids
Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants; [N: Measuring impedance or related variables]
Special rules of classification within this subgroup

The group G01R 27/26 represents only a parent-class which is not actively used. Instead the groups G01R 27/2605 - G01R 27/2688 are used.

In cases where an impedance with a real and an imaginary part is determined, and none of the groups listed hereabove are relevant, the group G01R 27/02 is used.

[N: Measuring capacitance (capacitive sensors G01D 5/24)]
Definition statement
This subclass/group covers:

The group covers:

Measurements of capacitance as such in the sense that particular steps of the measurement or particular features thereof are disclosed.

Only in very rare and exceptional cases where the capacity measurement has particular aspects capacitive sensors may be classified here.

References relevant to classification in this group
This subclass/group does not cover:

Examples of places where the subject matter of this subgroup is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Sensors using a capacitive element
Flow measurements
Temperature measurements
Pressure/ Force measurements
Analysing materials by capacitive methods
Acceleration measurements
Proximity switches
Special rules of classification within this group

The mere use of an existing capacity measurement method or device should not be classified in this group. In particular no sensors which are based on capacitance effects are classified here. Such sensors are classified in the classes of the corresponding applications.

[N: Measuring inductance]
Definition statement
This subclass/group covers:

The group covers:

Measurements of inductance as such in the sense that particular steps of the measurement or particular features thereof are disclosed.

Only in very rare and exceptional cases where the inductance measurement has particular aspects, sensors may be classified here.

References relevant to classification in this group
This subclass/group does not cover:

Examples of places where the subject matter of this subgroup is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Sensors using an inductive element
Flow measurements
Temperature measurements
Pressure/ Force measurements
Analysing materials by investigating the impedance
Acceleration measurements
[N: Measuring dielectric properties, e.g. constants (testing dielectric strength G01R 31/12; detecting insulation faults G01R 31/025; G01R 27/2688 takes precedence)]
Definition statement
This subclass/group covers:

Measurements of the relative permittivity

or electric susceptibility Xe

or the like of a dielectric material.

References relevant to classification in this group
This subclass/group does not cover:
Analysing materials by use of microwaves
Analysing materials by use of electric or magnetic means
Measuring quality factor or dielectric loss, e.g. loss angle, or power factor
Detecting insulation faults
Testing dielectric strength
[N: Measuring-systems or electronic circuits (G01R 27/2635, G01R 27/2682 take precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Sample holders, electrodes or excitation arrangements
Using optical methods or electron beams
[N: Bridge circuits (bridges for measuring loss angle G01R 27/2694)]
References relevant to classification in this group
This subclass/group does not cover:
Bridges for measuring loss angle
[N: Cavities, resonators, free space arrangements, reflexion or interference arrangements (G01R 27/2647 takes precedence; optical methods G01R 27/2682)]
References relevant to classification in this group
This subclass/group does not cover:
Sample holders, electrodes or excitation arrangements of coaxial or concentric type
Optical methods
[N: Measuring quality factor or dielectric loss, e.g. loss angle, or power factor (power factor related to power measurements G01R 21/006; testing capacitors G01R 31/016)]
Definition statement
This subclass/group covers:

Dielectric loss measurements e.g. of cables.

References relevant to classification in this group
This subclass/group does not cover:
Power factor related to power measurements
Measuring reflection coefficients, measuring standing-wave ratio
Testing capacitors
Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks, i.e. two-port networks [N: using network analysers] Measuring transient response (in line transmission systems H04B 3/46)
Definition statement
This subclass/group covers:

For example hf network analysers.

Relationship between large subject matter areas

Calibrations of network analysers are classified in G01R 35/005 and G01R 27/28 in parallel if the network analyser differs from known network analysers.

The use of known network analysers for special applications is classified in the corresponding classes of the applications, e.g. for analysis of materials in G01N 27/00.

References relevant to classification in this group
This subclass/group does not cover:
Measuring attenuation, gain, phase shift in line transmission systems
in circuits having distributed constants, [N: e.g. having very long conductors or involving high frequencies]
Definition statement
This subclass/group covers:

Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks whereby the wavelength comes into the geometrical order of the underlying medium, i.e. for very high frequencies, and this fact is essential for the invention.

Arrangements for measuring or indicating electric quantities not covered by groups G01R 19/00 to G01R 27/00
Measuring characteristics of individual pulses, e.g. deviation from pulse flatness, rise time, duration (of amplitude G01R 19/00; of repetition rate G01R 23/00; of phase difference of two cyclic pulse trains G01R 25/00; monitoring pattern of pulse trains H03K 5/19)
References relevant to classification in this group
This subclass/group does not cover:
Measuring peak values
Clock generators with changeable/programmable clock frequency
Manipulating pulses using a chain of active delay devices
Monitoring pattern of pulse trains
[N: the pulse characteristic being rise time (measuring rate of change 19/12)]
References relevant to classification in this group
This subclass/group does not cover:
Measuring rate of change
Measuring form factor, i.e. quotient of root-mean-square value and arithmetic mean of instantaneous value; Measuring peak factor, i.e. quotient of maximum value and root-mean-square value
References relevant to classification in this group
This subclass/group does not cover:
Measuring effective values, i.e. root-mean square values
Measuring depth of modulation
References relevant to classification in this group
This subclass/group does not cover:
Monitoring, testing of transmission systems
Measuring electromagnetic field characteristics [N: measuring electrostatic fields G01R 29/12; for determining a voltage G01R 15/14; measuring magnetic fields G01R 33/00; Receiver signal strength indication (RSSI) H04B 17/0042]
References relevant to classification in this group
This subclass/group does not cover:
Measuring electromagnetic field characteristics for determining a voltage or a current in a high voltage line, e.g. by using Hall elements
Measuring electrostatic fields
Measuring magnetic fields
Receiver signal strength indication (RSSI)
[N: Field measurements related to measuring influence on or from apparatus, components or humans (EMC, EMI and similar testing in general G01R 31/001), e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning]
Informative references
Attention is drawn to the following places, which may be of interest for search:
EMC, EMI and similar testing in general
[N: rooms and test sites therefor, e.g. anechoic chambers, open field sites or TEM cells (for testing antennas G01R 29/105)]
References relevant to classification in this group
This subclass/group does not cover:
Rooms and test sites for testing antennas
[N: for detecting presence or location of electric lines or cables (fault detection G01R 31/02; fault location G01R 31/08)]
References relevant to classification in this group
This subclass/group does not cover:
Testing of electric apparatus, lines or components for short circuits, discontinuities or leakage
Identification of wires in a multi-core cable
Locating faults in cables, transmission lines or networks
Electric or magnetic prospecting, e.g. for detecting hidden cables in walls
[N: Dosimetry, i.e. measuring the time integral of radiation intensity; Level warning devices for personal safety use (Nuclear radiation dosimetry G01T)]
References relevant to classification in this group
This subclass/group does not cover:
Nuclear radiation dosimetry
[N: characterised by constructional or functional features (not used, see subgroups)]
Special rules of classification within this subgroup

This group is not used, only the subgroups thereof are used.

[N: Complete apparatus or systems; circuits, e.g. receivers or amplifiers (G01R 29/0878, G01R 29/0892 take precedence; dosimeters, warning devices 29/08A3F)]
References relevant to classification in this group
This subclass/group does not cover:
Warning devices
Sensors; antennas; probes; detectors
Details related to signal analysis or treatment; presenting results
[N: Sensors; antennas; probes; detectors (Wave guide measuring sections G01R 1/24)]
References relevant to classification in this group
This subclass/group does not cover:
Wave guide measuring sections
Radiation diagrams of aerials; [N: Antenna testing in general]
Definition statement
This subclass/group covers:

Testing of antennas and/or measurements of radiation diagrams of aerials.

References relevant to classification in this group
This subclass/group does not cover:
Analysing the shape of a waveform
Antennas in general
Phased-array testing or checking devices
[N: using anechoic chambers; Chambers or open field sites used therefor (test sites used for measuring on other objects than aerials G01R 29/0828; wave absorbing devices H01Q 17/00)]
References relevant to classification in this group
This subclass/group does not cover:
Test sites used for measuring on other objects than aerials
Wave absorbing devices
Measuring electrostatic fields [N: or voltage-potential]
References relevant to classification in this group
This subclass/group does not cover:
Analysing materials by investigating electrostatic variables
Measuring field distribution
References relevant to classification in this group
This subclass/group does not cover:
Analysing materials by investigating electrostatic variables
Measuring radiation diagrams of antennas
Measuring asymmetry of polyphase networks
References relevant to classification in this group
This subclass/group does not cover:
Testing AC power supplies, e.g. frequency converters
Indicating phase sequence; Indicating synchronism
Definition statement
This subclass/group covers:

Indicating phase sequence or Indicating synchronism of power supply networks.

References relevant to classification in this group
This subclass/group does not cover:
Arrangements for synchronizing receiver with transmitter in communication networks
Measuring number of turns; Measuring transformation ratio or coupling factor of windings [N: Testing or] calibrating instrument transformers G01R 35/02)
References relevant to classification in this group
This subclass/group does not cover:
Testing of transformers for e.g. short circuits
Testing of electric windings
Testing or calibrating of instrument transformers
Transformers in general
Measuring piezo-electric properties
References relevant to classification in this group
This subclass/group does not cover:
Piezo-electric devices in general
Arrangements for measuring quantities of charge (electrostatic instruments G01R 5/28; indicating presence of current G01R 19/15; electrolytic meters, calorimetric meters, for measuring time integral of electric current G01R 22/02, G01R 22/04)
Relationship between large subject matter areas

The measurement of charge often goes together with the measurement of the electrostatic field.

The classes G01R 29/12, G01R 15/165 and G01R 5/28 should therefore also be considered and in cases where the measurement of the electrostatic field as such is also of particular interest one of these classes can be given in parallel to G01R 29/24. Otherwise G01R 29/24 takes precedence for charge measurements.

References relevant to classification in this group
This subclass/group does not cover:
Measuring electrostatic potential, e.g. with electrostatic voltmeters or electrometers, when the design of the sensor is essential
Indicating presence of current
Electrolytic meters, calorimetric meters, for measuring time integral of electric current
Measuring electrostatic fields
Electrostatic instruments
Measuring noise figure; Measuring signal-to-noise ratio [N: Measuring jitter, i.e. phase noise, (distortion G01R 23/20; noise measuring in individual transistors G01R 31/2616, G01R 31/2626)]
Definition statement
This subclass/group covers:

The measurement of noise figure, signal-to-noise ratio and of jitter (phase noise).

References relevant to classification in this group
This subclass/group does not cover:
Measurement of non-linear distortion, e.g. relation of harmonics to input signal
Analysis of signal quality or jitter of digital circuits
Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere (measuring leads, measuring probes G01R 1/06;[N: measuring superconductive properties G01R 33/1238; data processing equipment for testing or function monitoring G06F15/20B]; indicating electrical condition of switchgear or protective devices H01H 71/04, H01H 73/12, H02B 11/10, H02H 3/04; testing or measuring semiconductors or solid state devices during manufacture H01L21/66; testing substation equipment, e.g. mobile phones H04M 1/24; testing or monitoring of control systems G05B 23/02; [N: testing or monitoring transmitters or receivers H04B 17/00])
Definition statement
This subclass/group covers:

Electric testing of electric devices.

Special rules of classification within this group

When the testing concern circuits, one or more subgroup(s) of G01R 31/28 have priority.

Synonyms and Keywords

In patent documents the following abbreviations are often used:

DUT
device under test
[N: Environmental or reliability tests (of individual semiconductors G01R 31/2642; of PCB's G01R 31/2817; of IC's G01R 31/2855; of other circuits G01R 31/2849)]
Definition statement
This subclass/group covers:

Stress and burn-in testing, subjecting the DUT to hot or cold temperatures, radiation, vibration or similar.

[N: Testing of electric installations on transport means]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Safety, indicating or supervising devices for combustion engines.
[N: on air- or spacecraft, railway rolling stock or sea-going vessels]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Test or inspection of aircraft components or systems
Subjecting similar articles in turn to test, e.g. "go/no-go" tests in mass production; Testing objects at points as they pass through a testing station (G01R 31/18 takes precedence; [N: for testing batteries G01R 31/36 ])
Informative references
Attention is drawn to the following places, which may be of interest for search:
Sorting according to electric or electromagnetic properties
[N: Testing of capacitors (measuring capacitance G01R 27/2605)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Other testing of capacitors
Testing of electric apparatus, lines or components, for short circuits, discontinuities, leakage [N: of current], or incorrect line connection; [N: (G01R 31/001, G01R 31/005, G01R 31/01, G01R 31/08, G01R 31/12, G01R 31/24, G01R 31/26, G01R 31/28, G01R 31/327, G01R 31/34, G01R 31/36, G01R 31/40, G01R 31/44 take precedence; measuring electromagnetic field leakage G01R 29/0821); testing of sparking plugs H01T 13/58]
References relevant to classification in this group
This subclass/group does not cover:
Locating faults in cables, transmission lines, or networks
Testing dielectric strength or breakdown voltage
Testing of discharge tubes
Testing of individual semiconductor devices
Testing of electronic circuits
Testing of circuit interrupters, switches or circuit-breakers
Testing dynamo-electric machines
Apparatus for testing electrical condition of accumulators or electric batteries
Testing power supplies
Testing lamps
Informative references
Attention is drawn to the following places, which may be of interest for search:
Checking or monitoring of signalling or alarm systems
[N: Testing of cables or conductors (testing of electric windings G01R 31/06; testing of insulation of cables G01R 31/1272; testing of LAN`s H04L 12/2697; testing line transmission systems H04B 3/46)]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Monitoring, testing of line transmission systems for electric communication
Special rules of classification within this subgroup

The groups G01R 31/021, G01R 31/024, G01R 31/08 and G01R 31/12 are overlapping when it comes to testing of cables. An EC should be given in the most pertinent (sub)group, and additional EC's and or Indexing Code's in other valid places.

[N: Testing continuity (G01R 31/44 takes precedence)]
Definition statement
This subclass/group covers:

Tests for open circuits (lack of continuity) are classified here.

References relevant to classification in this group
This subclass/group does not cover:
Testing lamps
[N: Testing of capacitors]
References relevant to classification in this group
This subclass/group does not cover:
Go/no-go testing of capacitors
Informative references
Attention is drawn to the following places, which may be of interest for search:
Measuring of capacitance
Locating faults in cables, transmission lines, or networks (emergency protective circuit arrangements H02H) [N: (installing, maintaining, repairing or dismantling electric cables or lines H02G 1/00; testing LAN`s H04L 12/2697)]
Definition statement
This subclass/group covers:

Determining the exact location of a fault on a cable, transmission line or network.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Testing of circuits
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:

In this group, the following term is used with the meaning indicated:

Transmission line
Line, such as an aerial line, for transmitting electric power, e.g. from power plants to consumers.
using pulse reflection methods
Definition statement
This subclass/group covers:

Time domain and frequency domain reflectometry.

Synonyms and Keywords
TDR
time domain reflectometry
Testing dielectric strength or breakdown voltage; [N: Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing (G01R 31/06, G01R 31/08 and G01R 31/327 take precedence; measuring in plasmas G01R 19/0061; Measuring dielectric constants G01R 27/2617; ESD, EMC or EMP testing of circuits G01R 31/002)]
References relevant to classification in this group
This subclass/group does not cover:
Testing of circuit interrupters, switches or circuit-breakers of high voltage or medium voltage devices
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:

In this group, the following expression is used with the meaning indicated:

Dielectric strength or breakdown voltage
in addition to the immediate meaning, also: effectiveness or level of insulation; faulty insulation, e.g. so as to produce arcing faults.
Testing of individual semiconductor devices (measurement of impurity content of materials G01N)
References relevant to classification in this group
This subclass/group does not cover:
Testing of integrated circuits
Informative references
Attention is drawn to the following places, which may be of interest for search:
Testing or measuring semiconductor devices during manufacture
H01L21/66
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:

In this group, the following expression is used with the meaning indicated:

Individual semiconductor device
Basic semiconductor component or building block such as a diode or a transistor.
[N: for testing individual solar cells]
Relationship between large subject matter areas

This subgroup is to be moved out of G01R into the new subclass for solar cells/panels H02S whenever the receiving group there is created.

[N: Characterising semiconductor materials (testing of materials or semi-finished products G01R 31/2831; testing during manufacture H01L 22/00]
Special rules of classification within this subgroup

A raw wafer, not having any circuits or parts of circuits on it, is considered as an individual semiconductor element.

Testing of electronic circuits, e.g. by signal tracer ([N: EMC, EMP or similar testing of electronic circuits G01R 31/002]; testing for short-circuits, discontinuities, leakage or incorrect line connection G01R 31/02; checking computers [N: or computer components] G06F 11/00; checking static stores for correct operation G11C 29/00; [N: testing receivers or transmitters of transmission systems H04B 17/00])
Definition statement
This subclass/group covers:

Testing of printed circuits, integrated and hard-wired circuits.

References relevant to classification in this group
This subclass/group does not cover:
Testing transmission (electric communication) systems
Testing arrangements in data switching networks
Arrangements for testing substation (telephonic equipment) equipment
Informative references
Attention is drawn to the following places, which may be of interest for search:
Multiple probes
[N: Testing of printed circuits, backplanes, motherboards, hybrid circuits or carriers for multichip packages (MCP) (G01R 31/318508 takes precedence; contactless testing G01R 31/302; testing contacts or connections G01R 31/04)]
References relevant to classification in this group
This subclass/group does not cover:
Board Level Test
Informative references
Attention is drawn to the following places, which may be of interest for search:
Monitoring of manufacture of assemblages of electric components
Synonyms and Keywords

In patent documents the following abbreviations are often used:

PCB
Printed Circuit Board
MCP
multichip packages
[N: Aspects of quality control (QC) (G01R 31/31718 takes precedence; program control for QC G05B 19/41875)]
Definition statement
This subclass/group covers:

Statistical aspects of IC testing. Quality control procedures for IC testing.

References relevant to classification in this group
This subclass/group does not cover:
Logistic aspects
Informative references
Attention is drawn to the following places, which may be of interest for search:
Electric programme-control systems for total factory control
Data processing systems or methods for administration or managment
[N: Testing of IC packages; Test features related to IC packages (containers per se H01L 23/02, encapsulations per se H01L 23/28)]
Definition statement
This subclass/group covers:

Testing of integrated circuit packages as such, i.e. not involving the solid state circuits they surround.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
IC package
IC encapsulation
Contactless testing (non contact-making probes G01R 1/07) [N: (G01R 31/04 takes precedence)]
Definition statement
This subclass/group covers:

Testing of electric aspects of electronic circuits using contact-less exchange of information or energy, e.g. contact-less exciting or signal-sampling.

References relevant to classification in this group
This subclass/group does not cover:
Investigating flaws by inspecting patterns on the surface of objects
Image analysis
[N: Wireless interface with the DUT]
Definition statement
This subclass/group covers:

Wireless exchange of information between tester apparatus and DUT during electronic testing of integrated circuits.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Electromagnetic sensing of record carriers
Wireless transmission of measured values or control signals
Testing of circuit interrupters, switches or circuit-breakers (structural association with switches H01H; [N: detecting faults in encased switchgear H02B 13/065; monitoring in addition to disconnection by a protective circuit H02H 3/04])
Informative references
Attention is drawn to the following places, which may be of interest for search:
Testing contacts of switches, e.g. wear indicators
Gas insulated switchgear with means for detecting mechanical or electrical defects
Indication of state of electronic switch
Apparatus for testing electrical condition of accumulators or electric batteries, e.g. capacity or charge condition (accumulators combined with arrangements for measuring, testing or indicating condition H01M 10/48; circuit arrangements for charging, or depolarising batteries or for supplying loads from batteries H02J 7/00; [N: Coulomb meters G01R 22/00; indicating the condition of the power supply in clocks or watches G04C 10/04; methods for controlling fuel cells H01M 8/04298])
Definition statement
This subclass/group covers:

Testing of electrical conditions such as state of charge.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Current or voltage threshold detection in batteries.
Special rules of classification within this subgroup

The most specific subgroup is given priority, and other valid subgroups are added so that the document can be found by crossing subgroups.

Synonyms and Keywords
SoC
State of charge
SoH
State of Health
[N: Electrical testing of electrical aspects of solar panel power supplies (of individual solar cells G01R 31/2605)]
Special rules of classification within this group

This subgroup is seen to belong to the new subclass of solar panels H02S, and will be moved there once the new subclass has official subgroups for testing/monitoring.

Arrangements or instruments for measuring magnetic variables
Definition statement
This subclass/group covers:

Magnetic sensors and measuring aspects for measuring all kind of magnetic variables.

Special rules of classification within this group

NMR is classified in the subgroups of G01R 33/20, but general aspects of measuring magnetic variables is classified in G01R 33/0005-M.

Measuring direction or magnitude of magnetic fields or magnetic flux (G01R 33/20 takes precedence ; measuring direction or magnitude of the earth`s field for navigation or surveying G01C; for prospecting, for measuring the magnetic field of the earth G01V 3/00)
Definition statement
This subclass/group covers:

The different types of magnetic sensors.

Special rules of classification within this group

G01R 33/0005 to G01R 33/0052 concern general aspects of measuring magnetic variables and may also be given as additional class to the sub-classes of G01R 33/02.

[N: Three-component magnetometers]
Definition statement
This subclass/group covers:

3D Magnetometers.

[N: using deviation of charged particles by the magnetic field]
Definition statement
This subclass/group covers:

Apparatus and methods concerning measurements with charged or magnetic particles.

Measuring gradient
Definition statement
This subclass/group covers:

Gradiometers.

Compensating stray fields [N: (compensating compasses G01C 17/38)(G01R 33/0017 takes precedence)]
Definition statement
This subclass/group covers:

Devices using compensation measurements.

Electrodynamic magnetometers
Definition statement
This subclass/group covers:

Magnetometers using the relationship between currents, magnetic fields and/or magnetic force.

[N: comprising micro-electromechanical systems [MEMS] (MEMS devices in general B81B)]
Definition statement
This subclass/group covers:

All kind of MEMS devices.

using magneto-optic devices, e.g. Faraday, [N: Cotton-Mouton effect (magneto-optics in general G02F 1/09)]
Definition statement
This subclass/group covers:

All kind of magneto-optical devices and methods, e.g. Cotton-Mouton (magnetic double refraction in liquid, caused by lining-up of anisotropic molecules in magnetic field. Analogue of ELECTRO-optic Kerr effect, not related to Zeeman effect.)

[N: using the Faraday or Voigt effect]
Definition statement
This subclass/group covers:

e.g. Faraday effect (rotation of polarization plane of plane-polarized light, consequence of longitudinal Zeeman effect, field parallel to light beam); e.g. Voigt effect (magnetic double refraction, different diffraction for polarization parallel to field and polarization perpendicular to field, consequence of transverse Zeeman effect, field perpendicular to light beam)

[N: using the Kerr effect]
Definition statement
This subclass/group covers:

E.g. Kerr magneto-optic effect (normally incident plane-polarized light becomes elliptically polarized in magnetic field. To be distinguished from ordinary elliptical polarization under oblique incidence and from electro-optical Kerr effect).

[N: with application of magnetostriction]
Definition statement
This subclass/group covers:

All aspects concerning the relationship between strain/stress/shape/volume of a material and a magnetic field/the magnetic properties of the material.

using superconductive devices [N: (manufacture of superconducting elements H01L 39/00)]
Definition statement
This subclass/group covers:

SQUIDs and superconductive magneto-resistance.

[N: Superconductive magneto-resistances]
Definition statement
This subclass/group covers:

Magnetometers using the magneto-resistance in superconductors.

using the flux-gate principle
Definition statement
This subclass/group covers:

Fluxgate sensors.

in thin-film element
Definition statement
This subclass/group covers:

Micro-fluxgate sensors, e.g. manufactured in CMOS technology.

[N: Magneto-impedance sensors; Nanocristallin sensors]
Definition statement
This subclass/group covers:

Aspects concerning magneto-impedance.

[N: Constructional adaptation of the sensor to specific applications]
Definition statement
This subclass/group covers:

This class does not concern the sensors as such, but the adaptation of their environment for specific applications.

Magnetoresistive devices
Definition statement
This subclass/group covers:

AMR, GMR, TMR sensors.

[N: Constructional adaptation of the sensor to specific applications]
Definition statement
This subclass/group covers:

This class does not concern the sensors as such, but the adaptation of their environment for specific applications.

[N: using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F 10/00 )]
Definition statement
This subclass/group covers:

GMR, spin valve and AMR sensors.

[N: comprising tunnel junctions, e.g. tunnel magnetoresistance sensors]
Definition statement
This subclass/group covers:

TMR sensors.

Plotting field distribution; [N: Measuring field distribution]
Definition statement
This subclass/group covers:

Imaging of magnetic variables.

Measuring magnetic properties of articles or specimens of solids or fluids (involving magnetic resonance G01R 33/20) [N: using magnetic-optic devices G01R 33/032]
Definition statement
This subclass/group covers:

Aspects of measuring the different magnetic variables and may be classified in addition to the sub-classes of G01R 33/02.

Special rules of classification within this group

G01R 33/0005 to G01R 33/0052 may be considered additionally.

[N: Testing individual magnetic storage devices e.g. records carriers or digital storage elements (functional testing G06F 11/00, G06F 11/28)]
Definition statement
This subclass/group covers:

Qualification of hard disks and MRAMs.

[N: Measuring critical current]
Definition statement
This subclass/group covers:

Investigation of magnetic properties and critical current of super-conductors is classified.

[N: of molecules labeled with magnetic beads (magnetic particles for bio assay G01N 33/54326)]
Definition statement
This subclass/group covers:

Magnetic Biosensors.

[N: Spin resolved measurements; Influencing spins during measurements, e.g. in spintronics devices (G01R 33/093 takes precedence; semiconductor devices using spin polarized carriers H01L 29/66984)]
Definition statement
This subclass/group covers:

Spintronics devices.

[N: Measuring domain wall position or domain wall motion]
Definition statement
This subclass/group covers:

Aspects concerning domain wall analysis and racetrack memories.

Measuring or plotting hysteresis curves [N: G01R 33/1207 takes precedence]
Definition statement
This subclass/group covers:

Hysteresis measurements.

Measuring susceptibility [N: G01R 33/1238 takes precedence]
Definition statement
This subclass/group covers:

Aspects concerning magnetic susceptibility measurements.

involving magnetic resonance (medical aspects A61B 5/055; magnetic resonance gyrometers G01C 19/00[N: investigating materials using NMR G01N 24/00; prospecting or detecting using NMR G01V 3/00 ])
Definition statement
This subclass/group covers:

Equipment for making measurements involving magnetic resonance such as nuclear magnetic resonance [NMR], magnetic resonance imaging [MRI], electron paramagnetic resonance [EPR], nuclear quadrupole resonance [NQR] or other spin resonance effects;

Technical details of the equipment;

Testing or calibrating of the equipment;

Activities involved in making the measurements or in processing the signals collected during the measurements.

Relationship between large subject matter areas

The following places may also be relevant for classification:

A61B 5/055: Detecting, measuring or recording for diagnostic purposes

involving electronic or nuclear magnetic resonance

There is an overlap between the scope of G01R 33/20 (or its relevant subgroup) and A61B 5/055 in the sense that, depending on the disclosure of a given document, the document may have to be classified in G01R 33/20 (or its relevant subgroup) only, in A61B 5/055 only or in both places.

For instance, if the invention information of a document to be classified was primarily directed to the MR process as such (e.g. a novel pulse sequence which, according to the document, facilitates the diagnosis of a disease on the basis of the resulting MR images wherein the document merely mentions the diagnosis but does not specifically disclose its implementation in detail), the document should be classified in G01R 33/20 (or its relevant subgroup) and the additional information related to the diagnosis may be classified using the appropriate Indexing Code corresponding to A61B 5/055.

However, if the invention information of the document was primarily directed to the diagnosis as such (e.g. a novel way of processing MRI data in order to enable the diagnosis of a disease wherein the MRI data was acquired using a commonly known standard MRI technique), the document should be classified in A61B 5/055 only.

G01N 24/00 : Investigating or analysing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects

There is an overlap between the scope of G01R 33/20 (or its relevant subgroup) and G01N 24/00 (or its relevant subgroup) in the sense that, depending on the disclosure of a given document, the document may have to be classified in G01R 33/20 (or its relevant subgroup) only, in G01N 24/00 (or its relevant subgroup) only or in both places.

For instance, if the invention information of a document to be classified was primarily directed to the MR process as such (e.g. a novel pulse sequence which, according to the document, can be applied for analyzing materials wherein the document merely mentions this application but does not specifically disclose its implementation in detail), the document should be classified in G01R 33/20 (or its relevant subgroup) and the additional information related to the potential application for analyzing materials may be classified using the appropriate Indexing Code corresponding to G01N 24/00 (or its relevant subgroup).

However, if the invention information of the document was primarily directed to the analysis of a material using a known standard MR technique, the document should be classified in G01N 24/00 (or its relevant subgroup) only.

G01V 3/32: Electric or magnetic prospecting or detecting specially adapted for well-logging operating with electron or nuclear magnetic resonance

There is an overlap between the scope of G01R 33/20 (or its relevant subgroup) and G01V 3/32 in the sense that, depending on the disclosure of a given document, the document may have to be classified in G01R 33/20 (or its relevant subgroup) only, in G01V 3/32 only or in both places.

For instance, if the invention information of a document to be classified was primarily directed to the MR process as such (e.g. a novel pulse sequence which, according to the document, can be applied for MR in a borehole wherein the document merely mentions this application but does not specifically disclose its implementation in detail), the document should be classified in G01R 33/20 (or its relevant subgroup) and the additional information related to the potential application in the borehole may be classified using the appropriate Indexing Code of G01V 3/32.

However, if the invention information of the document was primarily directed to geophysics aspects or the application of MR in a borehole, the document should be classified in G01V 3/32 only.

References relevant to classification in this group
This subclass/group does not cover:
In vivo contrast agents
Magnetic resonance gyrometers
Omegatrons using ion cyclotron resonance

Examples of places where the subject matter of this subgroup is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects
Informative references
Attention is drawn to the following places, which may be of interest for search:
Detecting, measuring or recording for diagnostic purposes involving electronic or nuclear magnetic resonance
Means for positioning of patients
Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects
Electric or magnetic prospecting or detecting specially adapted for well-logging operating with electron or nuclear magnetic resonance
Two dimensional image generation, reconstruction from projection, e.g. tomography
Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
Cores, Yokes, or armatures
Coils
Superconducting magnets
Permanent magnets
Electromagnets
Aerials
Screening of an apparatus or of components against electric or magnetic fields
Special rules of classification within this subgroup

In this subgroup, classification of additional information, i.e. non-invention information, is compulsory using the appropriate Indexing Code (G01R 33/20 ...G01R 33/64).

Comments on subgroups:

G01R 33/323: For the purpose of classification in this subgroup, the expression "RF" is to be interpreted as referring to an RF magnetic field. Therefore, a document disclosing a technique of detecting MR using an RF electric field should be classified in this subgroup.

G01R 33/34046: For the purpose of classification in this subgroup, a "volume type coil" is to be understood as a coil which encloses the object to be investigated (in contrast to a surface coil which is positioned on a surface of the object to be investigated rather than enclosing the object).

G01R 33/34053: For the purpose of classification in this subgroup, a single-turn solenoid coil encircling the trunk of a patient to be investigated is understood as a volume type coil and therefore classified in subgroup G01R 33/34053.

In contrast thereto, a single-turn surface coil being placed on a surface of a patient is not understood as a volume type coil and should therefore not be classified in subgroup G01R 33/34053. Rather, classification symbol G01R 33/341 (or its subgroup G01R 33/3415) should be assigned in that case.

G01R 33/34061: For the purpose of classification in this subgroup, a Helmholtz coil is to be understood as any arrangement wherein two coils are placed symmetrically one on each side of the experimental area along a common axis.

Even if these coils are realized in the form of surface coils, the classification symbol G01R 33/341 should normally not be assigned.

G01R 33/34084 Implantable coils or coils being geometrically adaptable to the sample.

This subgroup does also cover coil assemblies with mutually movable parts, e.g. a Helmholtz coil assembly comprising two coils located on opposite sides of the trunk of a patient wherein the distance between the two coils can be adapted to the size of the trunk.

However, a single rigid surface coil which is mounted on a flexible mechanical support (e.g. a flexible arm) should not be classified in subgroup G01R 33/34084. Rather, classification symbol G01R 33/34007 should be assigned in that case.

G01R 33/3628: An RF coil being inductively matched to the transceiver in the sense that the RF coil is not galvanically connected to the transceiver, but only coupled to the transceiver via mutual inductance or mutual capacitance between the RF coil and a further coupling element (e.g. a driving coil), should not be classified in subgroup G01R 33/3628. Rather, classification symbol G01R 33/3642 should be assigned.

G01R 33/365 See comment under G01R 33/3657.

G01R 33/3657: For the purpose of classification in this subgroup as well as subgroup G01R 33/365, the "function" of the multiple RF coils is defined in relation to their use for spin excitation, MR signal reception or both.

For instance, an RF coil being used for exciting proton spins and another RF coil being used for exciting fluorine spins are therefore understood to perform the same function in MR, namely spin excitation.

G01R 33/4828: This group does not cover fat suppression which is to be classified under subgroup G01R 33/5607.

G01R 33/565: This subgroup does also cover the prevention of image distortions.

For instance, an RF coil being manufactured from susceptibility compensated wire, thereby preventing image distortions due to magnetic susceptibility variations, should be classified in the appropriate subgroup of G01R 33/565, probably using the corresponding Indexing Code (G01R 33/56536 in the example given above).

G01R 33/62: This subgroup covers the combined use of at least two different spin resonance techniques, e.g. the combined use of NMR and NQR.

This group does not cover RF coils being resonant at two distinct Larmor frequencies. Rather, such RF coils are covered by subgroup G01R 33/3635.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
NMR
nuclear magnetic resonance
EMR
electron magnetic resonance
EPR
electron paramagnetic resonance
ESR
electron spin resonance
MRI
magnetic resonance imaging
NQR
nuclear quadrupole resonance
Testing or calibrating of apparatus covered by the preceding groups [N: (G01R 31/31901 takes precedence)]
References relevant to classification in this group
This subclass/group does not cover:
Calibration of tester hardware for testing digital circuits
[N: Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references (G01R 33/0035, G01R 35/002 take precedence)]
Definition statement
This subclass/group covers:

Calibrating of measuring devices such as network analysers, but also other measuring devices of the preceding groups.

References relevant to classification in this group
This subclass/group does not cover:
Calibration of single magnetic sensors
[N: Standards or reference devices, e.g. voltage or resistance standards, "golden references"]
Definition statement
This subclass/group covers:

Standards or reference devices comprising new aspects and being new over standards known in the art.

of auxiliary devices, e.g. of instrument tranformers according to prescribed transformation ratio, phase angle, or wattage rating
Informative references
Attention is drawn to the following places, which may be of interest for search:
Measuring number of turns, measuring transformation ratio
Testing of electric windings
of instruments for measuring time integral of power or current
Informative references
Attention is drawn to the following places, which may be of interest for search:
Electromechanical arrangements for measuring time integral of electric power or current
Other arrangements for measuring time integral of electric power or current, e.g. by electronic methods
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Last Modified: 10/11/2013