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).
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 Fulltext... Hierarchy... Expanded...G01 and "control" and "regulation" in class Fulltext... Hierarchy... Expanded...G05.
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 (Fulltext... Hierarchy... Expanded...G09), for enabling the result of a measurement to be known (Fulltext... Hierarchy... Expanded...G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...G01L) or about some other condition linked to the pressure (another subclass of class Fulltext... Hierarchy... Expanded...G01, e.g., Fulltext... Hierarchy... Expanded...G01K for temperature), to make a record of the pressure or of its occurrence (Fulltext... Hierarchy... Expanded...G07C), to give an alarm (Fulltext... Hierarchy... Expanded...G08B), or to control another apparatus (Fulltext... Hierarchy... Expanded...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.
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.
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.
Attention is drawn to the Notes following the title of section G, especially as regards the definition of the term "variable".
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 Fulltext... Hierarchy... Expanded...G01D for expression of the measurement, and finally the place for the overall system, if any. [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 Fulltext... Hierarchy... Expanded...G01B.
General constructional details (details of a kind applicable to measuring arrangements not specially adapted for a specific variable Fulltext... Hierarchy... Expanded...G01D 7/00)
G01R 1/04
· ·
Housings; Supporting members; Arrangements of terminals
having both fixed and moving coils, i.e. dynamometers
G01R 7/18
· · ·
with iron core magnetically coupling fixed and moving coils
P:40
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
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 Fulltext... Hierarchy... Expanded...B60L 3/00)
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
using analogue/digital converters of the type with conversion of voltage or current into frequency and measuring of this frequency [4]
G01R 19/255
· ·
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 [4]
G01R 19/257
· ·
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 [4]
G01R 19/28
·
adapted for measuring in circuits having distributed constants
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]
An arrangement for measuring time integral of electric power is classified in group Fulltext... Hierarchy... Expanded...G01R 21/00 if the essential characteristic is the measuring of electric power. [4]
G01R 22/02
·
by electrolytic methods [4]
G01R 22/04
·
by calorimetric methods [4]
G01R 22/06
·
by electronic methods [8]
G01R 22/08
· ·
using analogue techniques [8]
G01R 22/10
· ·
using digital techniques [8]
P:130
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
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]
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 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
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
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
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 (Fulltext... Hierarchy... Expanded...G01R 31/18 takes precedence) [6]
G01R 31/02
·
Testing of electric apparatus, lines, or components for short-circuits, discontinuities, leakage, or incorrect line connection
G01R 31/04
· ·
Testing connections, e.g. of plugs, of non-disconnectable joints
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]