|  | G |
SECTION G — PHYSICS

INSTRUMENTS

|  | G01 |
MEASURING (counting Fulltext... Hierarchy... Expanded...G06M); TESTING

|  | G01R |
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 Fulltext... Hierarchy... Expanded...G01; measuring diffusion of ions in an electric field, e.g. electrophoresis, electro-osmosis, Fulltext... Hierarchy... Expanded...G01N; investigating non-electric or non-magnetic properties of materials by using electric or magnetic methods Fulltext... Hierarchy... Expanded...G01N; indicating correct tuning of resonant circuits Fulltext... Hierarchy... Expanded...H03J 3/12; monitoring electronic pulse counters Fulltext... Hierarchy... Expanded...H03K 21/34; monitoring operation of communication systems Fulltext... Hierarchy... Expanded...H04)

|  | G01R |
Note(s) Attention is drawn to the notes immediately following the class title (Fulltext... Hierarchy... Expanded...G01). This sub-class deals with (a) measuring all kinds of electric and magnetic variables directly or by derivation from other electric or magnetic variables; (b) measuring all kinds of electric and magnetic properties of materials; (c) testing electric and magnetic devices, apparatus, and networks (e.g. discharge tubes, amplifiers) and measuring their characteristics; (d) indicating presence or sign of current or voltage; (e) equipment for generating signals to be used for carrying out such tests and measurements. The expression "measuring" is used to include investigating. In this sub-class: The expression "arrangements for measuring" is used to mean "apparatus, circuits, or methods for measuring". Electric measuring instruments of the general types dealt with in groups Fulltext... Hierarchy... Expanded...G01R 5/00, Fulltext... Hierarchy... Expanded...G01R 7/00, Fulltext... Hierarchy... Expanded...G01R 9/00 but specially adapted for measuring a specific variable, e.g. frequency, phase, impedance, are dealt with in the groups relevant to such variables. Group Fulltext... Hierarchy... Expanded...G01R 17/00 takes precedence over groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01R 19/00-G01R 31/00.

|  | G01R 1/00 |
Details of instruments of the types included in groups Fulltext... Hierarchy... Expanded...G01R 5/00, Fulltext... Hierarchy... Expanded...G01R 7/00, Fulltext... Hierarchy... Expanded...G01R 9/00, Fulltext... Hierarchy... Expanded...G01R 11/00, Fulltext... Hierarchy... Expanded...G01R 13/00 (constructional details particular to instruments for measuring the time integral of electric power or current Fulltext... Hierarchy... Expanded...G01R 11/02)

|  | G01R 1/02 |
· | General constructional details (details of a kind applicable to indicating instruments in general Fulltext... Hierarchy... Expanded...G01D)

|  | G01R 1/04 |
· · | Housings; Supporting members; Arrangements of terminals (terminals Fulltext... Hierarchy... Expanded...H01R; terminal strips or boards Fulltext... Hierarchy... Expanded...H02B; housings for electrical apparatus Fulltext... Hierarchy... Expanded...H05K)

|  | G01R 1/06 |
· · | Measuring leads; Measuring probes (Fulltext... Hierarchy... Expanded...G01R 19/145, Fulltext... Hierarchy... Expanded...G01R 19/165 take precedence; end pieces for leads Fulltext... Hierarchy... Expanded...H01R 11/00)

|  | G01R 1/067 |
· · · | Measuring probes [3]

|  | G01R 1/073 |
· · · · | Multiple probes [3]

|  | G01R 1/08 |
· · | Pointers; Scales, Scale illumination

|  | G01R 1/10 |
· · | Arrangements of bearings (bearings in general Fulltext... Hierarchy... Expanded...F16C)

|  | G01R 1/12 |
· · · | of strip or wire bearings

|  | G01R 1/14 |
· · | Braking arrangements; Damping arrangements

|  | G01R 1/16 |
· · | Magnets (in general Fulltext... Hierarchy... Expanded...H01F)

|  | G01R 1/18 |
· · | Screening arrangements against electric or magnetic fields, e.g. against earth's field

|  | G01R 1/20 |
· | Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments (instrument transformers per se Fulltext... Hierarchy... Expanded...H01F 40/00)

|  | G01R 1/22 |
· · | Tong testers acting as secondary windings of current transformers

|  | G01R 1/24 |
· · | Transmission-line, e.g. waveguide, measuring sections, e.g. slotted section

|  | G01R 1/26 |
· · · | with linear movement of probe

|  | G01R 1/28 |
· | Provision in measuring instruments for reference values, e.g. standard voltage, standard waveform

|  | G01R 1/30 |
· | Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier

|  | G01R 1/36 |
· | Overload-protection arrangements or circuits for electric measuring instruments (in general Fulltext... Hierarchy... Expanded...H02H)

|  | G01R 1/38 |
· | Arrangements for altering the indicating characteristic, e.g. by modifying the air gap (circuits Fulltext... Hierarchy... Expanded...G01R 15/10)

|  | G01R 1/40 |
· | Modifications of instruments to indicate the maximum or the minimum value reached in a time interval, e.g. by maximum indicator pointer

|  | G01R 1/42 |
· · | thermally operated

|  | G01R 1/44 |
· | Modifications of instruments for temperature compensation [2]

|  | G01R 3/00 |
Apparatus or processes specially adapted for the manufacture of measuring instruments

|  | G01R 5/00 |
Instruments for converting a single current or a single voltage into a mechanical displacement (vibration galvanometers Fulltext... Hierarchy... Expanded...G01R 9/02)

|  | G01R 5/02 |
· | Moving-coil instruments

|  | G01R 5/04 |
· · | with magnet external to the coil

|  | G01R 5/06 |
· · | with core magnet

|  | G01R 5/08 |
· · | specially adapted for wide angle deflection; with eccentrically-pivoted moving coil

|  | G01R 5/10 |
· | String galvanometers

|  | G01R 5/12 |
· | Loop galvanometers

|  | G01R 5/14 |
· | Moving-iron instruments

|  | G01R 5/16 |
· · | with pivoting magnet

|  | G01R 5/18 |
· · | with pivoting soft iron, e.g. needle galvanometer

|  | G01R 5/20 |
· | Induction instruments e.g. Ferraris instruments

|  | G01R 5/22 |
· | Thermoelectric instruments (thermocouple instruments Fulltext... Hierarchy... Expanded...G01R 19/24)

|  | G01R 5/24 |
· · | operated by elongation of a strip or wire or by expansion of a gas or fluid

|  | G01R 5/26 |
· · | operated by deformation of a bimetallic element

|  | G01R 5/28 |
· | Electrostatic instruments (combined with radiation detector Fulltext... Hierarchy... Expanded...G01T)

|  | G01R 5/30 |
· · | Leaf electrometers

|  | G01R 5/32 |
· · | Wire electrometers; Needle electrometers

|  | G01R 5/34 |
· · | Quadrant electrometers

|  | G01R 7/00 |
Instruments capable of converting two or more currents or voltages into a single mechanical displacement (Fulltext... Hierarchy... Expanded...G01R 9/00 takes precedence)

|  | G01R 7/02 |
· | for forming a sum or a difference

|  | G01R 7/04 |
· | for forming a quotient (for measuring resistance Fulltext... Hierarchy... Expanded...G01R 27/08)

|  | G01R 7/06 |
· · | moving-iron type

|  | G01R 7/08 |
· · | moving-coil type, e.g. crossed-coil type

|  | G01R 7/10 |
· · · | having more than two moving coils

|  | G01R 7/12 |
· | for forming product

|  | G01R 7/14 |
· · | moving-iron type

|  | G01R 7/16 |
· · | having both fixed and moving coils, i.e. dynamometers

|  | G01R 7/18 |
· · · | with iron core magnetically coupling fixed and moving coils

|  | G01R 9/00 |
Instruments employing mechanical resonance

|  | G01R 9/02 |
· | Vibration galvanometers, e.g. for measuring current

|  | G01R 9/04 |
· | using vibrating reeds, e.g. for measuring frequency

|  | G01R 9/06 |
· · | magnetically driven

|  | G01R 9/08 |
· · | piezo-electrically driven

|  | G01R 11/00 |
Instruments for measuring the time integral of electric power or current

|  | G01R 11/02 - G01R 11/46 |
Note(s) Groups Fulltext... Hierarchy... Expanded...G01R 11/48, Fulltext... Hierarchy... Expanded...G01R 11/56 take precedence over groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01R 11/30-G01R 11/46.

|  | G01R 11/02 |
· | Constructional details (applicable to electric measuring instruments in general Fulltext... Hierarchy... Expanded...G01R 1/00)

|  | G01R 11/04 |
· · | Housings; Supporting racks; Arrangements of terminals

|  | G01R 11/06 |
· · | Magnetic circuits of induction meters [2]

|  | G01R 11/067 |
· · · | Coils therefor [2]

|  | G01R 11/073 |
· · · | Armatures therefor [2]

|  | G01R 11/09 |
· · · · | Disc armatures [2]

|  | G01R 11/10 |
· · | Braking magnets; Damping arrangements

|  | G01R 11/12 |
· · | Arrangements of bearings (bearings in general Fulltext... Hierarchy... Expanded...F16C)

|  | G01R 11/14 |
· · · | with magnetic relief

|  | G01R 11/16 |
· · | Adaptations of counters to electricity meters (counters per se Fulltext... Hierarchy... Expanded...G06M)

|  | G01R 11/17 |
· · | Compensating for errors; Adjusting or regulating means therefor [2]

|  | G01R 11/18 |
· · · | Compensating for variations in ambient conditions [2]

|  | G01R 11/185 |
· · · · | Temperature compensation [2]

|  | G01R 11/19 |
· · · | Compensating for errors caused by disturbing torque, e.g. rotating-field errors of polyphase meters [2]

|  | G01R 11/20 |
· · · | Compensating for phase errors in induction meters [2]

|  | G01R 11/21 |
· · · | Compensating for errors caused by damping effects of the current, e.g. adjustment in the overload range [2]

|  | G01R 11/22 |
· · · | Adjusting torque, e.g. adjusting starting torque, adjusting of polyphase meters for obtaining equal torques [2]

|  | G01R 11/23 |
· · · | Compensating for errors caused by friction, e.g. adjustment in the light-load range [2]

|  | G01R 11/24 |
· | Arrangements for avoiding or indicating fraudulent use

|  | G01R 11/25 |
· | Fault-indicating or -signalling devices in electricity meters [2]

|  | G01R 11/30 |
· | Dynamo-electric motor meters

|  | G01R 11/32 |
· · | Watt-hour meters

|  | G01R 11/34 |
· · | Ampere-hour meters

|  | G01R 11/36 |
· | Induction meters, e.g. Ferraris meters (Ferraris instruments Fulltext... Hierarchy... Expanded...G01R 5/20)

|  | G01R 11/38 |
· · | for single-phase operation

|  | G01R 11/40 |
· · | for polyphase operation

|  | G01R 11/42 |
· · · | Circuitry therefor

|  | G01R 11/44 |
· | Electrolytic meters; Calorimetric meters

|  | G01R 11/46 |
· | Electrically-operated clockwork meters; Oscillatory meters; Pendulum meters

|  | G01R 11/48 |
· | Meters specially adapted for measuring real or reactive components; Meters specially adapted for measuring apparent energy

|  | G01R 11/50 |
· · | for measuring real component

|  | G01R 11/52 |
· · | for measuring reactive component

|  | G01R 11/54 |
· · | for measuring simultaneously at least two of the following three variables: real component, reactive component, apparent energy

|  | G01R 11/56 |
· | Special tariff meters (tariff metering in general Fulltext... Hierarchy... Expanded...G01D 4/00)

|  | G01R 11/57 |
· · | Multi-rate meters (Fulltext... Hierarchy... Expanded...G01R 11/63 takes precedence) [2]

|  | G01R 11/58 |
· · · | Tariff-switching devices therefor [2]

|  | G01R 11/60 |
· · | Subtraction meters; Meters measuring maximum- or minimum-load hours

|  | G01R 11/63 |
· · | Over-consumption meters, e.g. measuring consumption while a predetermined level of power is exceeded [2]

|  | G01R 11/64 |
· · | Maximum meters, e.g. tariff for a period is based on maximum demand within that period

|  | G01R 11/66 |
· · · | Circuitry

|  | G01R 13/00 |
Instruments for displaying electric variables or waveforms (display by mechanical displacement only Fulltext... Hierarchy... Expanded...G01R 5/00, Fulltext... Hierarchy... Expanded...G01R 7/00, Fulltext... Hierarchy... Expanded...G01R 9/00; recording frequency spectrum Fulltext... Hierarchy... Expanded...G01R 23/18; indicating or recording measured values in general Fulltext... Hierarchy... Expanded...G01D)

|  | G01R 13/02 |
· | Instruments for displaying measured electric variables in digital form (counters Fulltext... Hierarchy... Expanded...G06M; analogue/digital conversion Fulltext... Hierarchy... Expanded...H03K 13/02)

|  | G01R 13/04 |
· | Arrangements for producing permanent records of electric variables or waveforms

|  | G01R 13/06 |
· · | Modifications for recording transient disturbances, e.g. by starting or accelerating a recording medium

|  | G01R 13/08 |
· · | Electromechanical recording system using a mechanical direct-writing method

|  | G01R 13/10 |
· · · | with intermittent recording by representing the variable by the length of a stroke or by the position of a dot

|  | G01R 13/12 |
· · | Chemical recording, e.g. clydonographs (Fulltext... Hierarchy... Expanded...G01R 13/14 takes precedence)

|  | G01R 13/14 |
· · | Recording on a light-sensitive material

|  | G01R 13/16 |
· · | Recording on a magnetic medium

|  | G01R 13/18 |
· · · | using boundary displacement

|  | G01R 13/20 |
· | Cathode-ray oscilloscopes (cathode-ray tubes Fulltext... Hierarchy... Expanded...H01J 31/00)

|  | G01R 13/22 |
· · | Circuits therefor (generating pulses, e.g. sawtooth waveforms Fulltext... Hierarchy... Expanded...H03K 3/00)

|  | G01R 13/24 |
· · · | Time-base deflection circuits

|  | G01R 13/26 |
· · · | Circuits for controlling the intensity of the electron beam (brilliance control Fulltext... Hierarchy... Expanded...H01J 29/98)

|  | G01R 13/28 |
· · · | Circuits for simultaneous or sequential presentation of more than one variable (electronic switches Fulltext... Hierarchy... Expanded...H03K 17/00)

|  | G01R 13/30 |
· · · | Circuits for inserting reference markers, e.g. for timing, for calibrating, for frequency marking

|  | G01R 13/32 |
· · · | Circuits for displaying non-recurrent functions such as transients; Circuits for triggering; Circuits for synchronisation; Circuits for time-base expansion

|  | G01R 13/34 |
· · · | Circuits for representing a single waveform by sampling, e.g. for very high frequencies (sample-and-hold arrangements Fulltext... Hierarchy... Expanded...G11C 27/02) [2]

|  | G01R 13/36 |
· | Instruments using length of glow discharge, e.g. glowlight oscilloscopes (discharge tubes Fulltext... Hierarchy... Expanded...H01J)

|  | G01R 13/38 |
· | Instruments using the steady or oscillatory displacement of a light beam by an electromechanical measuring system (such measuring systems per se Fulltext... Hierarchy... Expanded...G01R 5/00, Fulltext... Hierarchy... Expanded...G01R 7/00, Fulltext... Hierarchy... Expanded...G01R 9/00)

|  | G01R 13/40 |
· | Instruments using modulation of a light beam otherwise than by mechanical displacement, e.g. by Kerr effect

|  | G01R 13/42 |
· | Instruments using length of spark discharge, e.g. by measuring maximum separation of electrodes to produce spark

|  | G01R 15/00 |
Details of measuring arrangements (details of instruments Fulltext... Hierarchy... Expanded...G01R 1/00; overload protection arrangements or circuits Fulltext... Hierarchy... Expanded...G01R 1/36)

|  | G01R 15/02 |
· | Adaptation for high-voltage networks; Adaptation for high-current networks (instrument transformers Fulltext... Hierarchy... Expanded...H01F 40/00)

|  | G01R 15/04 |
· · | using voltage dividers

|  | G01R 15/06 |
· · · | having reactive components

|  | G01R 15/07 |
· · | using modulation of electromagnetic waves, e.g. light beams (modulation of light per se Fulltext... Hierarchy... Expanded...G02F 1/00) [2]

|  | G01R 15/08 |
· | Circuits for altering the measuring range

|  | G01R 15/10 |
· | Circuits for altering the indicating characteristic, e.g. making it non-linear

|  | G01R 15/12 |
· | Circuits for multi-testers, e.g. for measuring voltage, current, or impedance at will

|  | G01R 17/00 |
Measuring arrangements involving comparison with a reference value, e.g. bridge

|  | G01R 17/02 |
· | Arrangements in which the value to be measured is automatically compared with a reference value

|  | G01R 17/04 |
· · | in which the reference value is continuously or periodically swept over the range of values to be measured

|  | G01R 17/06 |
· · | Automatic balancing arrangements

|  | G01R 17/08 |
· · · | in which a force or torque representing the measured value is balanced by a force or torque representing the reference value

|  | G01R 17/10 |
· | ac or dc measuring bridges (automatic comparison or re-balancing arrangements Fulltext... Hierarchy... Expanded...G01R 17/02)

|  | G01R 17/12 |
· · | using comparison of currents, e.g. bridges with differential current output

|  | G01R 17/14 |
· · | with indication of measured value by calibrated null indicator, e.g. percent bridge, tolerance bridge (Fulltext... Hierarchy... Expanded...G01R 17/12, Fulltext... Hierarchy... Expanded...G01R 17/16 take precedence)

|  | G01R 17/16 |
· · | with discharge tubes or semiconductor devices in one or more arms of the bridge, e.g. voltmeter using a difference amplifier

|  | G01R 17/18 |
· · | with more than four branches

|  | G01R 17/20 |
· | ac or dc potentiometric measuring arrangements (automatic comparison or re-balancing arrangements Fulltext... Hierarchy... Expanded...G01R 17/02)

|  | G01R 17/22 |
· · | with indication of measured value by calibrated null indicator

|  | G01R 19/00 |
Arrangements for measuring currents or voltages or for indicating presence or sign thereof (for measuring bio-electric currents or voltages Fulltext... Hierarchy... Expanded...A61B 5/04)

|  | G01R 19/02 - G01R 19/30 |
Note(s) In this main group, group Fulltext... Hierarchy... Expanded...G01R 19/28 takes precedence over all the other groups; groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01R 19/18-G01R 19/25 take precedence over groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01R 19/02-G01R 19/165 and Fulltext... Hierarchy... Expanded...G01R 19/30. [3]

|  | G01R 19/02 |
· | Measuring effective values, i.e. root-mean-square values

|  | G01R 19/04 |
· | Measuring peak values of ac or of pulses [2]

|  | G01R 19/06 |
· | Measuring real component; Measuring reactive component

|  | G01R 19/08 |
· | Measuring current density

|  | G01R 19/10 |
· | Measuring sum, difference, or ratio

|  | G01R 19/12 |
· | Measuring rate of change

|  | G01R 19/14 |
· | Indicating direction of current; Indicating polarity of voltage

|  | G01R 19/145 |
· | Indicating the presence of current or voltage [3]

|  | G01R 19/15 |
· · | Indicating the presence of current [3]

|  | G01R 19/155 |
· · | Indicating the presence of voltage [3]

|  | G01R 19/16 |
( transferred to Fulltext... Hierarchy... Expanded...G01R 19/145, Fulltext... Hierarchy... Expanded...G01R 19/165 )

|  | G01R 19/165 |
· | 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 Fulltext... Hierarchy... Expanded...H03K 3/00; threshold switches Fulltext... Hierarchy... Expanded...H03K 17/00) [3]

|  | G01R 19/17 |
· · | giving an indication of the number of times this occurs [3]

|  | G01R 19/175 |
· | Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero [3]

|  | G01R 19/18 |
· | using conversion of dc into ac, e.g. with choppers

|  | G01R 19/20 |
· · | using transductors

|  | G01R 19/22 |
· | using conversion of ac into dc

|  | G01R 19/24 |
· · | using thermocouples

|  | G01R 19/25 |
· | using digital measurement techniques (instruments for displaying measured electric variables in digital form Fulltext... Hierarchy... Expanded...G01R 13/02; analogue/digital conversion per se Fulltext... Hierarchy... Expanded...H03K 13/02) [3]

|  | G01R 19/26 |
( transferred to Fulltext... Hierarchy... Expanded...G01R 19/25, covered by Fulltext... Hierarchy... Expanded...G01R 19/00 )

|  | G01R 19/28 |
· | adapted for measuring in circuits having distributed constants

|  | G01R 19/30 |
· | Measuring the maximum or the minimum value of current or voltage reached in a time interval (Fulltext... Hierarchy... Expanded...G01R 19/04 takes precedence; modifications of instruments to indicate the maximum or the minimum value reached in a time interval Fulltext... Hierarchy... Expanded...G01R 1/40) [2]

|  | G01R 19/32 |
· | Compensating for temperature change [2]

|  | G01R 21/00 |
Arrangements for measuring electric power, power factor, or energy (monitoring power consumption of electrically-propelled vehicles Fulltext... Hierarchy... Expanded...B60L 3/00) [2]

|  | G01R 21/01 |
· | in circuits having distributed constants (Fulltext... Hierarchy... Expanded...G01R 21/04, Fulltext... Hierarchy... Expanded...G01R 21/07, Fulltext... Hierarchy... Expanded...G01R 21/09, Fulltext... Hierarchy... Expanded...G01R 21/12 take precedence) [2]

|  | G01R 21/02 |
· | by thermal methods, e.g. calorimetric [2]

|  | G01R 21/04 |
· · | in circuits having distributed constants

|  | G01R 21/06 |
· | by measuring current and voltage

|  | G01R 21/07 |
· · | in circuits having distributed constants (Fulltext... Hierarchy... Expanded...G01R 21/09 takes precedence) [2]

|  | G01R 21/08 |
· | by using galvanomagnetic-effect devices, e.g. Hall-effect devices (such devices per se Fulltext... Hierarchy... Expanded...H01L) [2]

|  | G01R 21/09 |
· · | in circuits having distributed constants [2]

|  | G01R 21/10 |
· | by using square-law characteristics of circuit elements, e.g. diodes, to measure power absorbed by loads of known impedance (Fulltext... Hierarchy... Expanded...G01R 21/02 takes precedence) [2]

|  | G01R 21/12 |
· · | in circuits having distributed constants

|  | G01R 21/14 |
· | Compensating for temperature change [2]

|  | G01R 23/00 |
Arrangements for measuring frequencies; Arrangements for analysing frequency spectra (frequency discriminators Fulltext... Hierarchy... Expanded...H03D)

|  | G01R 23/02 |
· | Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage (measuring short time intervals Fulltext... Hierarchy... Expanded...G04F)

|  | G01R 23/04 |
· · | adapted for measuring in circuits having distributed constants

|  | G01R 23/06 |
· · | by converting frequency into an amplitude of current or voltage

|  | G01R 23/07 |
· · · | using response of circuits tuned on resonance, e.g. grid-drip meter [2]

|  | G01R 23/08 |
· · · | using response of circuits tuned off resonance

|  | G01R 23/09 |
· · · | 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 Fulltext... Hierarchy... Expanded...G01T 1/15) [2]

|  | G01R 23/10 |
· · | by converting frequency into a train of pulses, which are then counted (counters per se Fulltext... Hierarchy... Expanded...G06M, Fulltext... Hierarchy... Expanded...H03K)

|  | G01R 23/12 |
· · | by converting frequency into phase shift

|  | G01R 23/14 |
· · | by heterodyning; by beat-frequency comparison (generation of oscillations by beating unmodulated signals of different frequencies Fulltext... Hierarchy... Expanded...H03B 21/00) [2]

|  | G01R 23/15 |
· · | 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 [3]

|  | G01R 23/16 |
· | Spectrum analysis; Fourier analysis

|  | G01R 23/163 |
· · | adapted for measuring in circuits having distributed constants [3]

|  | G01R 23/165 |
· · | using filters [3]

|  | G01R 23/167 |
· · · | with digital filters [3]

|  | G01R 23/17 |
· · | with optical auxiliary devices [3]

|  | G01R 23/173 |
· · | Wobbulating devices similar to swept panoramic receivers (panoramic receivers per se Fulltext... Hierarchy... Expanded...H03J 7/32) [3]

|  | G01R 23/175 |
· · | by delay means, e.g. tapped delay lines [3]

|  | G01R 23/177 |
· · | Analysis of very low frequencies [3]

|  | G01R 23/18 |
· · | with provision for recording frequency spectrum

|  | G01R 23/20 |
· · | Measurement of non-linear distortion

|  | G01R 25/00 |
Arrangements for measuring phase angle between a voltage and a current or between voltages or currents (measuring power factor Fulltext... Hierarchy... Expanded...G01R 21/00; measuring position of individual pulses in a pulse train Fulltext... Hierarchy... Expanded...G01R 29/02; phase discriminators Fulltext... Hierarchy... Expanded...H03D) [2]

|  | G01R 25/02 |
· | in circuits having distributed constants

|  | G01R 25/04 |
· | involving adjustment of a phase shifter to produce a predetermined phase difference, e.g. zero difference

|  | G01R 25/06 |
· | employing quotient instrument

|  | G01R 25/08 |
· | by counting of standard pulses (measuring time intervals Fulltext... Hierarchy... Expanded...G04F) [2]

|  | G01R 27/00 |
Arrangements for measuring resistance, reactance, impedance, or characteristics derived therefrom

|  | G01R 27/02 |
· | Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant (by measuring phase angle only Fulltext... Hierarchy... Expanded...G01R 25/00)

|  | G01R 27/04 |
· · | in circuits having distributed constants

|  | G01R 27/06 |
· · · | Measuring reflection coefficients; Measuring standing-wave ratio

|  | G01R 27/08 |
· · | Measuring resistance by measuring both voltage and current

|  | G01R 27/10 |
· · · | using two-coil or crossed-coil instruments forming quotient

|  | G01R 27/12 |
· · · · | using hand generators, e.g. meggers

|  | G01R 27/14 |
· · | Measuring resistance by measuring current or voltage obtained from a reference source (Fulltext... Hierarchy... Expanded...G01R 27/16, Fulltext... Hierarchy... Expanded...G01R 27/20, Fulltext... Hierarchy... Expanded...G01R 27/22 take precedence)

|  | G01R 27/16 |
· · | Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line

|  | G01R 27/18 |
· · · | Measuring resistance to earth

|  | G01R 27/20 |
· · | Measuring earth resistance; Measuring contact resistance of earth connections, e.g. plates

|  | G01R 27/22 |
· · | Measuring resistance of fluids (measuring vessels, electrodes therefor Fulltext... Hierarchy... Expanded...G01N 27/07)

|  | G01R 27/26 |
· · | Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants

|  | G01R 27/28 |
· | Measuring attenuation, gain, phase shift, or derived characteristics of electric four-pole networks, i.e. two-port networks; Measuring transient response (in line transmission systems Fulltext... Hierarchy... Expanded...H04B 3/46)

|  | G01R 27/30 |
· · | with provision for recording characteristics, e.g. by plotting Nyquist diagram

|  | G01R 27/32 |
· · | in circuits having distributed constants [2]

|  | G01R 29/00 |
Arrangements for measuring or indicating electric quantities not covered by groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01R 19/00-G01R 27/00

|  | G01R 29/02 |
· | Measuring characteristics of individual pulses, e.g. deviation from pulse flatness, rise time, duration (of amplitude Fulltext... Hierarchy... Expanded...G01R 19/00; of repetition rate Fulltext... Hierarchy... Expanded...G01R 23/00; of phase difference of two cyclic pulse trains Fulltext... Hierarchy... Expanded...G01R 25/00; monitoring pattern of pulse trains Fulltext... Hierarchy... Expanded...H03K 5/19)

|  | G01R 29/027 |
· · | Indicating that a pulse characteristic is either above or below a predetermined value or within or beyond a predetermined range of values [3]

|  | G01R 29/033 |
· · · | giving an indication of the number of times this occurs [3]

|  | G01R 29/04 |
· | 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

|  | G01R 29/06 |
· | Measuring depth of modulation

|  | G01R 29/08 |
· | Measuring electromagnetic field characteristics

|  | G01R 29/10 |
· · | Radiation diagrams of aerials

|  | G01R 29/12 |
· | Measuring electrostatic fields

|  | G01R 29/14 |
· · | Measuring field distribution

|  | G01R 29/16 |
· | Measuring asymmetry of polyphase networks

|  | G01R 29/18 |
· | Indicating phase sequence; Indicating synchronism

|  | G01R 29/20 |
· | Measuring number of turns; Measuring transformation ratio or coupling factor of windings (calibrating instrument transformers Fulltext... Hierarchy... Expanded...G01R 35/02)

|  | G01R 29/22 |
· | Measuring piezo-electric properties

|  | G01R 29/24 |
· | Arrangements for measuring quantities of charge (electrostatic instruments Fulltext... Hierarchy... Expanded...G01R 5/28; electrolytic meters, calorimetric meters for measuring the time integral of electric current Fulltext... Hierarchy... Expanded...G01R 11/44; indicating presence of current G 01 R 19/16) [2]

|  | G01R 29/26 |
· | Measuring noise figure; Measuring signal-to-noise ratio [2]

|  | G01R 31/00 |
Arrangements for testing electric properties; Arrangements for locating electric faults (detecting the presence of an arc or discharge in switches Fulltext... Hierarchy... Expanded...H01H 9/50, Fulltext... Hierarchy... Expanded...H01H 33/26; indicating electrical condition of switchgear or protective devices Fulltext... Hierarchy... Expanded...H01H 71/04, Fulltext... Hierarchy... Expanded...H01H 73/12, Fulltext... Hierarchy... Expanded...H02B 11/10, Fulltext... Hierarchy... Expanded...H02H 3/04; indicating condition of fuses Fulltext... Hierarchy... Expanded...H01H 85/30; testing line transmission systems Fulltext... Hierarchy... Expanded...H04B 3/46)

|  | G01R 31/02 |
· | Testing of electric apparatus, lines, and components for short-circuits, discontinuities, leakage, or incorrect line connection

|  | G01R 31/04 |
· · | Testing connections, e.g. of plugs, of non-disconnectable joints

|  | G01R 31/06 |
· · | Testing of electric windings, e.g. for polarity (measuring number of turns, transformation ratio, or coupling factor Fulltext... Hierarchy... Expanded...G01R 29/20)

|  | G01R 31/08 |
· | Locating faults in cables, transmission lines, or networks (emergency protective circuit arrangements Fulltext... Hierarchy... Expanded...H02H)

|  | G01R 31/10 |
· · | by increasing destruction at fault, e.g. burning-in by using a pulse generator operating a special programme

|  | G01R 31/11 |
· · | using pulse-reflection methods

|  | G01R 31/12 |
· | Testing of articles or specimens of solids or fluids for dielectric strength or breakdown voltage

|  | G01R 31/14 |
· · | Circuits therefor

|  | G01R 31/16 |
· · | Construction of testing vessels; Electrodes therefor

|  | G01R 31/18 |
· · | Subjecting similar articles in turn to test, e.g. go/no-go tests in mass production

|  | G01R 31/20 |
· · | Preparation of articles or specimens to facilitate testing

|  | G01R 31/24 |
· | Testing of discharge tubes (during manufacture Fulltext... Hierarchy... Expanded...H01J 9/42) [2]

|  | G01R 31/25 |
· · | Testing of vacuum tubes [2]

|  | G01R 31/26 |
· | Testing of individual semiconductor devices (measurement of impurity content of materials Fulltext... Hierarchy... Expanded...G01N) [2]

|  | G01R 31/28 |
· | Testing of electronic circuits, e.g. by signal tracer (checking computers Fulltext... Hierarchy... Expanded...G06F 11/00; checking static stores for correct operation Fulltext... Hierarchy... Expanded...G11C 29/00)

|  | G01R 31/30 |
· · | Marginal testing, e.g. by varying supply voltage (marginal testing of computers Fulltext... Hierarchy... Expanded...G06) [2]

|  | G01R 31/32 |
· | Testing of the switching capacity of high-voltage circuit-breakers (means for detecting the presence of an arc or discharge in switching devices Fulltext... Hierarchy... Expanded...H01H 9/50, Fulltext... Hierarchy... Expanded...H01H 33/26) [2]

|  | G01R 31/34 |
· | Testing dynamo-electric machines (testing electric windings Fulltext... Hierarchy... Expanded...G01R 31/06; methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing dynamo-electric machines Fulltext... Hierarchy... Expanded...H02K 15/00) [3]

|  | G01R 31/36 |
· | 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 Fulltext... Hierarchy... Expanded...H01M 10/48; circuit arrangements for charging, or depolarising batteries or for supplying loads from batteries Fulltext... Hierarchy... Expanded...H02J 7/00) [3]

|  | G01R 33/00 |
Arrangements or instruments for measuring magnetic variables

|  | G01R 33/02 |
· | Measuring direction or magnitude of magnetic fields or magnetic flux (measuring direction or magnitude of the earth's field for navigation or surveying Fulltext... Hierarchy... Expanded...G01C; for prospecting, for measuring the magnetic field of the earth Fulltext... Hierarchy... Expanded...G01V 3/00)

|  | G01R 33/022 - G01R 33/09 |
Note(s) Groups Fulltext... Hierarchy... Expanded...G01R 33/022, Fulltext... Hierarchy... Expanded...G01R 33/10 take precedence over groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01R 33/025-G01R 33/09.

|  | G01R 33/022 |
· · | Measuring gradient [3]

|  | G01R 33/025 |
· · | Compensating stray fields [3]

|  | G01R 33/028 |
· · | Electrodynamic magnetometers [3]

|  | G01R 33/032 |
· · | using magneto-optic devices, e.g. Faraday [3]

|  | G01R 33/035 |
· · | using super-conductive devices [3]

|  | G01R 33/038 |
· · | using permanent magnets, e.g. balances, torsion devices [3]

|  | G01R 33/04 |
· · | using the flux-gate principle

|  | G01R 33/05 |
· · · | in thin-film element [3]

|  | G01R 33/06 |
· · | using galvano-magnetic devices, e.g. Hall effect, magneto resistance

|  | G01R 33/08 |
· · | using electronic or nuclear magnetic resonance

|  | G01R 33/09 |
· · · | using optical pumping [3]

|  | G01R 33/10 |
· · | Plotting field distribution

|  | G01R 33/12 |
· | Measuring magnetic properties of articles or specimens of solids or fluids

|  | G01R 33/14 |
· · | Measuring or plotting hysteresis curves

|  | G01R 33/16 |
· · | Measuring susceptibility

|  | G01R 33/18 |
· · | Measuring magnetostrictive properties

|  | G01R 35/00 |
Testing or calibrating of apparatus covered by the preceding groups [2]

|  | G01R 35/02 |
· | of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating

|  | G01R 35/04 |
· | of instruments for measuring time integral of power or current

|  | G01R 35/06 |
· · | by stroboscopic methods