G
SECTION G — PHYSICS
 G

Note(s)

  1. In this section, the following term is used with the meaning indicated:
    • "variable" (as a noun) means a feature or property (e.g., a dimension, a physical condition such as temperature, a quality such as density or colour) which, in respect of a particular entity (e.g., an object, a quantity of a substance, a beam of light) and at a particular instant, is capable of being measured; the variable may change, so that its numerical expression may assume different values at different times, in different conditions or in individual cases, but may be constant in respect of a particular entity in certain conditions or for practical purposes (e.g., the length of a bar may be regarded as constant for many purposes).
  2. Attention is drawn to the definitions of terms or expressions used, appearing in the notes of several of the classes in this section, in particular those of "measuring" in class G01 and "control" and "regulation" in class G05.
  3. Classification in this section may present more difficulty than in other sections, because the distinction between different fields of use rests to a considerable extent on differences in the intention of the user rather than on any constructional differences or differences in the manner of use, and because the subjects dealt with are often in effect systems or combinations, which have features or parts in common, rather than "things", which are readily distinguishable as a whole. For example, information (e.g., a set of figures) may be displayed for the purpose of education or advertising (G09), for enabling the result of a measurement to be known (G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (G08). The words used to describe the purpose depend on features that may be irrelevant to the form of the apparatus concerned, for example, such features as the desired effect on the person who sees the display, or whether the display is controlled from a remote point. Again, a device which responds to some change in a condition, e.g., in the pressure of a fluid, may be used, without modification of the device itself, to give information about the pressure (G01L) or about some other condition linked to the pressure (another subclass of class G01, e.g., G01K for temperature), to make a record of the pressure or of its occurrence (G07C), to give an alarm (G08B), or to control another apparatus (G05).

    The classification scheme is intended to enable things of a similar nature (as indicated above) to be classified together. It is therefore particularly necessary for the real nature of any technical subject to be decided before it can be properly classified.

  
INSTRUMENTS
 G01
MEASURING (counting G06M); TESTING
 G01

Note(s)

  1. This class covers, in addition to "true" measuring instruments, other indicating or recording devices of analogous construction, and also signalling or control devices insofar as they are concerned with measurement (as defined in Note 2 below) and are not specially adapted to the particular purpose of signalling or control.
  2. In this class, the following term is used with the meaning indicated:
    • "measuring" is used to cover considerably more than its primary or basic meaning. In this primary sense, it means finding a numerical expression of the value of a variable in relation to a unit or datum or to another variable of the same nature, e.g. expressing a length in terms of another length as in measuring a length with a scale; the value may be obtained directly (as just suggested) or by measuring some other variable of which the value can be related to the value of the required variable, as in measuring a change in temperature by measuring a resultant change in the length of a column of mercury. However, since the same device or instrument may, instead of giving an immediate indication, be used to produce a record or to initiate a signal to produce an indication or control effect, or may be used in combination with other devices or instruments to give a conjoint result from measurement of two or more variables of the same or different kinds, it is necessary to interpret "measuring" as including also any operation that would make it possible to obtain such a numerical expression by the additional use of some way of converting a value into figures. Thus the expression in figures may be actually made by a digital presentation or by reading a scale, or an indication of it may be given without the use of figures, e.g. by some perceptible feature (variable) of the entity (e.g. object, substance, beam of light) of which the variable being measured is a property or condition or by an analogue of such a feature (e.g. the corresponding position of a member without any scale, a corresponding voltage generated in some way). In many cases there is no such value indication but only an indication of difference or equality in relation to a standard or datum (of which the value may or may not be known in figures); the standard or datum may be the value of another variable of the same nature but of a different entity (e.g. a standard measure) or of the same entity at a different time.

      In its simplest form, measurement may give merely an indication of presence or absence of a certain condition or quality, e.g. movement (in any direction or in a particular direction), or whether a variable exceeds a predetermined value.

  3. Attention is drawn to the Notes following the titles of class B81 and subclass B81B relating to "micro-structural devices" and "micro-structural systems" and the Notes following the title of subclass B82B relating to "nano-structures". [7]
  4. Attention is drawn to the Notes following the title of section G, especially as regards the definition of the term "variable".
  5. In many measuring arrangements, a first variable to be measured is transformed into a second, or further, variables. The second, or further, variables may be (a) a condition related to the first variable and produced in a member, or (b) a displacement of a member. Further transformation may be needed.  [6]

    When classifying such an arrangement, (i) the transformation step, or each transformation step, that is of interest is classified, or (ii) if interest lies only in the system as a whole, the first variable is classified in the appropriate place.  [6]

    This is particularly important where two or more conversions take place, for instance where a first variable, for example pressure, is transformed into a second variable, for example an optical property of a sensing body, and that second variable is expressed by means of a third variable, for example an electric effect. In such a case, the following classification places should be considered: the place for the transformation of the first variable, that for sensing the condition caused by that variable, subclass G01D for expression of the measurement, and finally the place for the overall system, if any.  [6]

  6. The measurement of change in the value of a physical property is classified in the same subclass as the measurement of that physical property, e.g. measurement of expansion of length is classified in subclass G01B.
 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 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 3/00; monitoring electronic pulse counters H03K 21/00; monitoring operation of communication systems H04)
 G01R

Note(s)

  1. This subclass covers:
    • measuring all kinds of electric or magnetic variables directly or by derivation from other electric or magnetic variables;
    • measuring all kinds of electric or magnetic properties of materials;
    • testing electric or magnetic devices, apparatus or networks (e.g. discharge tubes, amplifiers) or measuring their characteristics;
    • indicating presence or sign of current or voltage;
    • NMR, EPR or other spin-effect apparatus, not specially adapted for a particular application; [5]
    • equipment for generating signals to be used for carrying out such tests and measurements.
  2. In this subclass, the following terms or expressions are used with the meanings indicated:
    • "measuring" includes investigating;
    • "instruments" or "measuring instruments" means electro-mechanical measuring mechanisms;
    • "arrangements for measuring" means apparatus, circuits, or methods for measuring;
  3. Attention is drawn to the Notes following the title of class G01.
  4. In this subclass, instruments or arrangements for measuring electric variables are classified in the following way: [8]
  5. In this subclass, group G01R 17/00 takes precedence over groups G01R 19/00-G01R 31/00.
 G01R
Subclass index
ELECTRIC MEASURING INSTRUMENTS
In general 5/00, 7/00, 9/00
Details 1/00
Manufacture; calibrating, testing 3/00; 35/00
ELECTROMECHANICAL MEASUREMENT OF TIME INTEGRAL OF POWER OR CURRENT 11/00
MEASURING ELECTRIC VARIABLES
Details of measuring arrangements 11/00, 15/00
Arrangements for displaying 13/00
Involving comparison with a reference value 17/00
Current or voltage; power, power factor; time integral of power or current; frequency; resistance, reactance, impedance 19/00; 21/00; 22/00; 23/00; 27/00
Other variables 25/00, 29/00
TESTING ELECTRIC PROPERTIES OR LOCATING FAULTS 31/00
MEASURING MAGNETIC VARIABLES 33/00
P:80 G01R 1/00
Details of instruments or arrangements of the types included in groups G01R 5/00-G01R 13/00 and G01R 31/00 (constructional details particular to arrangements for measuring the electric consumption G01R 11/00)  [3,8]
 G01R 1/02
·  General constructional details (details of a kind applicable to measuring arrangements not specially adapted for a specific variable G01D 7/00)
 G01R 1/06
·  ·  Measuring leads; Measuring probes (G01R 19/145, G01R 19/165 take precedence; end pieces for leads H01R 11/00)  [3]
 G01R 1/067
·  ·  ·  Measuring probes  [3]
 G01R 1/073
·  ·  ·  ·  Multiple probes  [3]
P:180 G01R 3/00
Apparatus or processes specially adapted for the manufacture of measuring instruments
P:60 G01R 5/00
Instruments for converting a single current or a single voltage into a mechanical displacement (vibration galvanometers G01R 9/00)
P:50 G01R 7/00
Instruments capable of converting two or more currents or voltages into a single mechanical displacement (G01R 9/00 takes precedence)
P:40 G01R 9/00
Instruments employing mechanical resonance
P:30 G01R 11/00
Electromechanical arrangements for measuring time integral of electric power or current, e.g. of consumption (monitoring electric consumption of electrically-propelled vehicles B60L 3/00)
P:70 G01R 13/00
Arrangements for displaying electric variables or waveformes (display by mechanical displacement only G01R 5/00, G01R 7/00, G01R 9/00; recording frequency spectrum G01R 23/16)  [4]
 G01R 13/20
·  Cathode-ray oscilloscopes (cathode-ray tubes H01J 31/00)
 G01R 13/22
·  ·  Circuits therefor (circuits for generating pulses, e.g. sawtooth waveforms H03K 3/00)
P:170 G01R 15/00
Details of measuring arrangements of the types provided for in groups G01R 17/00-G01R 29/00, G01R 33/00-G01R 33/24 and G01R 35/00 (details of instruments G01R 1/00; measuring leads, measuring probes G01R 1/06; overload protection arrangements G01R 1/00; circuits for correcting the transfer function G01D 3/02)  [1,8]
 G01R 15/14
·  Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks (voltage dividers G01R 15/00)  [6]
 G01R 15/24
·  ·  using light-modulating devices  [6]
P:90 G01R 17/00
Measuring arrangements involving comparison with a reference value, e.g. bridge
P:120 G01R 19/00
Arrangements for measuring currents or voltages or for indicating presence or sign thereof (G01R 5/00 takes precedence; for measuring bioelectric currents or voltages A61B 5/04)  [4]
 G01R 19/02 - 
G01R 19/32

Note(s)

Within groups G01R 19/02-G01R 19/32, group G01R 19/28 takes precedence. Groups G01R 19/18-G01R 19/25 take precedence over groups G01R 19/02-G01R 19/165 and 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 19/165
·  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 H03K 3/00; threshold switches 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 19/22
·  using conversion of ac into dc
 G01R 19/25
·  using digital measurement techniques (arrangements for displaying measured electric variables in digital form G01R 13/00)  [3]
 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 (G01R 19/04 takes precedence; modifications of instruments to indicate the maximum or the minimum value reached in a time interval G01R 1/00)  [2,3]
 G01R 19/32
·  Compensating for temperature change (modifications of instruments for temperature compensation G01R 1/00)  [2]
P:100 G01R 21/00
Arrangements for measuring electric power or power factor (G01R 7/00 takes precedence)  [4]
P:110 G01R 22/00
Arrangements for measuring time integral of electric power or current, e.g. electricity meters (electromechanical arrangements therefor G01R 11/00; monitoring electric consumption of electrically-propelled vehicles B60L 3/00)  [4,8]
 G01R 22/00

Note(s)

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.  [4]

 G01R 22/06
·  by electronic methods  [8]
P:130 G01R 23/00
Arrangements for measuring frequencies; Arrangements for analysing frequency spectra (frequency discriminators H03D)
 G01R 23/16
·  Spectrum analysis; Fourier analysis
 G01R 23/20
·  ·  Measurement of non-linear distortion
P:140 G01R 25/00
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)  [2]
P:150 G01R 27/00
Arrangements for measuring resistance, reactance, impedance, or electric 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 G01R 25/00)
 G01R 27/04
·  ·  in circuits having distributed constants
 G01R 27/08
·  ·  Measuring resistance by measuring both voltage and current
 G01R 27/14
·  ·  Measuring resistance by measuring current or voltage obtained from a reference source (G01R 27/16, G01R 27/20, 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 27/20
·  ·  Measuring earth resistance; Measuring contact resistance of earth connections, e.g. plates
 G01R 27/22
·  ·  Measuring resistance of fluids (measuring vessels, electrodes therefor G01N 27/06)
 G01R 27/26
·  ·  Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants
P:160 G01R 29/00
Arrangements for measuring or indicating electric quantities not covered by groups 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 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)  [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 29/24
·  Arrangements for measuring quantities of charge (electrostatic instruments G01R 5/00; indicating presence of current G01R 19/145; arrangements for measuring time integral of electric power or current G01R 22/00)  [2]
P:10 G01R 31/00
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; indicating electrical condition of switchgear or protective devices H01H 71/04, H01H 73/00, H02B 11/00, H02H 3/02; testing or measuring semiconductors or solid state devices during manufacture H01L 21/66; testing line transmission systems H04B 3/46)
 G01R 31/01
·  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 31/12 takes precedence)  [6]
 G01R 31/02
·  Testing of electric apparatus, lines, or components for short-circuits, discontinuities, leakage, or incorrect line connection
 G01R 31/08
·  Locating faults in cables, transmission lines, or networks (emergency protective circuit arrangements H02H)
 G01R 31/12
·  Testing dielectric strength or breakdown voltage
 G01R 31/24
·  Testing of discharge tubes (during manufacture H01J 9/42)  [2]
 G01R 31/26
·  Testing of individual semiconductor devices (measurement of impurity content of materials G01N)  [2]
 G01R 31/28
·  Testing of electronic circuits, e.g. by signal tracer (testing for short-circuits, discontinuities, leakage or incorrect line connection G01R 31/02; checking computers G06F 11/00; checking static stores for correct operation or testing static stores during standby or offline operation G11C 29/00)
 G01R 31/327
·  Testing of circuit interrupters, switches or circuit-breakers (structural association with switches H01H)  [6]
 G01R 31/34
·  Testing dynamo-electric machines (testing electric windings G01R 31/02; methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing dynamo-electric machines 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 H01M 10/42; circuit arrangements for charging, or depolarising batteries or for supplying loads from batteries H02J 7/00)  [3]
 G01R 31/38
·  Testing of sparking-plugs (testing non-electrical properties G01M 19/02)  [6]
 G01R 31/40
·  Testing power supplies  [6]
 G01R 31/44
·  Testing lamps (discharge lamps G01R 31/24; structurally associated with light source circuit arrangements for detecting lamp failure H05B 37/00)  [6]
P:20 G01R 33/00
Arrangements or instruments for measuring magnetic variables
 G01R 33/02
·  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)  [4]
 G01R 33/022
·  ·  Measuring gradient  [3]
 G01R 33/025 - 
G01R 33/06

Note(s)

Group G01R 33/022 or group G01R 33/10 takes precedence over groups G01R 33/025-G01R 33/06.

 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 superconductive devices  [3]
 G01R 33/038
·  ·  using permanent magnets, e.g. balances, torsion devices  [3]
 G01R 33/04
·  ·  using the flux-gate principle
 G01R 33/06
·  ·  using galvano-magnetic devices
 G01R 33/10
·  ·  Plotting field distribution
 G01R 33/12
·  Measuring magnetic properties of articles or specimens of solids or fluids (involving magnetic resonance G01R 33/20)  [4]
 G01R 33/16
·  ·  Measuring susceptibility
 G01R 33/18
·  ·  Measuring magnetostrictive properties
 G01R 33/20
·  involving magnetic resonance (medical aspects A61B 5/055; magnetic resonance gyrometers G01C 19/58)  [4,5]
 G01R 33/24
·  ·  for measuring direction or magnitude of magnetic fields or magnetic flux  [4]
 G01R 33/28
·  ·  Details of apparatus provided for in groups G01R 33/44-G01R 33/64  [5]
 G01R 33/30
·  ·  ·  Sample handling arrangements, e.g. sample cells, spinning mechanisms  [5]
 G01R 33/32
·  ·  ·  Excitation or detection systems, e.g. using radiofrequency signals  [5]
 G01R 33/34
·  ·  ·  ·  Constructional details, e.g. resonators  [5]
 G01R 33/38
·  ·  ·  Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field  [5]
 G01R 33/44
·  ·  using nuclear magnetic resonance (NMR) (G01R 33/24, G01R 33/62 take precedence)  [5]
 G01R 33/48
·  ·  ·  NMR imaging systems  [5]
 G01R 33/54
·  ·  ·  ·  Signal processing systems, e.g. using pulse sequences  [5]
 G01R 33/60
·  ·  using electron paramagnetic resonance (G01R 33/24, G01R 33/62 take precedence)  [5]
 G01R 33/62
·  ·  using double resonance (G01R 33/24 takes precedence)  [5]
 G01R 33/64
·  ·  using cyclotron resonance (G01R 33/24 takes precedence)  [5]
P:0 G01R 35/00
Testing or calibrating of apparatus covered by the other groups of this subclass  [2]