|  | G |
SECTION G — PHYSICS

|  | G |
Note(s) 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.

INSTRUMENTS

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

|  | G01 |
Note(s) 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 titles of class Fulltext... Hierarchy... Expanded...B81 and subclass Fulltext... Hierarchy... Expanded...B81B relating to "micro-structural devices" and "micro-structural systems" and the Notes following the title of subclass Fulltext... Hierarchy... Expanded...B82B relating to "nano-structures". [7] 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.

|  | G01M |
TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

|  | G01M |
Note(s) Attention is drawn to the Notes following the title of class Fulltext... Hierarchy... Expanded...G01.

|  | G01M |
Subclass index
TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES | 1/00
INVESTIGATING FLUID-TIGHTNESS; ELASTICITY | 3/00; 5/00
VIBRATION- OR SHOCK-TESTING | 7/00
SPECIAL APPLICATIONS |
Aerodynamic; hydrodynamic testing | 9/00; 10/00
Optical testing | 11/00
Mechanical or engine testing | 13/00, 15/00, 17/00
OTHER TESTING OF STRUCTURES OR OF APPARATUS NOT PROVIDED FOR ELSEWHERE | 19/00

P:10 |  | G01M 1/00 |
Testing static or dynamic balance of machines or structures (balancing rotary bowls of centrifuges Fulltext... Hierarchy... Expanded...B04B 9/14; apparatus characterised by the means for holding wheels or parts thereof Fulltext... Hierarchy... Expanded...B60B 30/00; determining stability factors of ships Fulltext... Hierarchy... Expanded...B63B; stabilising of aircraft Fulltext... Hierarchy... Expanded...B64C 17/00; control systems for balancing automatically in operation Fulltext... Hierarchy... Expanded...G05; balancing rotors of dynamo-electric machines Fulltext... Hierarchy... Expanded...H02K 15/16)

|  | G01M 1/02 |
· | Details of balancing machines or devices

|  | G01M 1/04 |
· · | Adaptation of bearing support assemblies for receiving the body to be tested

|  | G01M 1/06 |
· · | Adaptation of drive assemblies for receiving the body to be tested

|  | G01M 1/08 |
· · | Instruments for indicating directly the magnitude and phase of the unbalance (measuring electrical variables in general Fulltext... Hierarchy... Expanded...G01R)

|  | G01M 1/10 |
· | Determining the moment of inertia

|  | G01M 1/12 |
· | Static balancing; Determining position of centre of gravity (by determining unbalance Fulltext... Hierarchy... Expanded...G01M 1/14)

|  | G01M 1/14 |
· | Determining unbalance (Fulltext... Hierarchy... Expanded...G01M 1/30, Fulltext... Hierarchy... Expanded...G01M 1/38 take precedence)

|  | G01M 1/16 |
· · | by oscillating or rotating the body to be tested

|  | G01M 1/18 |
· · · | and running the body down from a speed greater than normal

|  | G01M 1/20 |
· · · | and applying external forces compensating forces due to unbalance

|  | G01M 1/22 |
· · · | and converting vibrations due to unbalance into electric variables (measuring vibrations in general Fulltext... Hierarchy... Expanded...G01H; microphones or like acoustic electromechanical transducers Fulltext... Hierarchy... Expanded...H04R)

|  | G01M 1/24 |
· · · | Performing balancing on elastic shafts, e.g. for crankshafts

|  | G01M 1/26 |
· · · | with special adaptations for marking, e.g. by drilling

|  | G01M 1/28 |
· · · | with special adaptations for determining unbalance of the body in situ, e.g. of vehicle wheels

|  | G01M 1/30 |
· | Compensating unbalance (Fulltext... Hierarchy... Expanded...G01M 1/38 takes precedence; counterweights Fulltext... Hierarchy... Expanded...F16F 15/28)

|  | G01M 1/32 |
· · | by adding material to the body to be tested, e.g. by correcting-weights (correcting-weights per se Fulltext... Hierarchy... Expanded...F16F 15/32)

|  | G01M 1/34 |
· · | by removing material from the body to be tested, e.g. from the tread of tyres

|  | G01M 1/36 |
· · | by adjusting position of masses built-in the body to be tested

|  | G01M 1/38 |
· | Combined machines or devices for both determining and correcting unbalance

P:20 |  | G01M 3/00 |
Investigating fluid tightness of structures (investigating permeability of porous material, investigating the presence of flaws in general Fulltext... Hierarchy... Expanded...G01N)

|  | G01M 3/02 |
· | by using fluid or vacuum

|  | G01M 3/04 |
· · | by detecting the presence of fluid at the leakage point

|  | G01M 3/06 |
· · · | by observing bubbles in a liquid pool

|  | G01M 3/08 |
· · · · | for pipes, cables, or tubes; for pipe joints or seals; for valves

|  | G01M 3/10 |
· · · · | for containers, e.g. radiators

|  | G01M 3/12 |
· · · | by observing elastic covers or coatings, e.g. soapy water

|  | G01M 3/14 |
· · · · | for pipes, cables, or tubes; for pipe joints or seals; for valves

|  | G01M 3/16 |
· · · | using electric detection means (Fulltext... Hierarchy... Expanded...G01M 3/06, Fulltext... Hierarchy... Expanded...G01M 3/12, Fulltext... Hierarchy... Expanded...G01M 3/20, Fulltext... Hierarchy... Expanded...G01M 3/24, Fulltext... Hierarchy... Expanded...G01M 3/26 take precedence)

|  | G01M 3/18 |
· · · · | for pipes, cables, or tubes; for pipe joints or seals; for valves

|  | G01M 3/20 |
· · · | using special tracer materials, e.g. dye, fluorescent material, radioactive material

|  | G01M 3/22 |
· · · · | for pipes, cables, or tubes; for pipe joints or seals; for valves

|  | G01M 3/24 |
· · · | using infrasonic, sonic, or ultrasonic vibrations

|  | G01M 3/26 |
· · | by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors [2]

|  | G01M 3/28 |
· · · | for pipes, cables, or tubes; for pipe joints or seals; for valves [2]

|  | G01M 3/30 |
· · · · | using progressive displacement of one fluid by another [2]

|  | G01M 3/32 |
· · · | for containers, e.g. radiators [2]

|  | G01M 3/34 |
· · · · | by testing the possibility of maintaining the vacuum in containers, e.g. in can-testing machines [2]

|  | G01M 3/36 |
· · | by detecting change in dimensions of the structure being tested

|  | G01M 3/38 |
· | by using light (Fulltext... Hierarchy... Expanded...G01M 3/02 takes precedence)

|  | G01M 3/40 |
· | by using electric means, e.g. by observing electric discharges

P:50 |  | G01M 5/00 |
Investigating the elasticity of structures, e.g. deflection of bridges, aircraft wings (Fulltext... Hierarchy... Expanded...G01M 9/00 takes precedence; strain gauges Fulltext... Hierarchy... Expanded...G01B)

P:60 |  | G01M 7/00 |
Vibration-testing of structures; Shock-testing of structures (Fulltext... Hierarchy... Expanded...G01M 9/00 takes precedence)

|  | G01M 7/02 |
· | Vibration-testing [5]

|  | G01M 7/04 |
· · | Monodirectional test stands [5]

|  | G01M 7/06 |
· · | Multidirectional test stands [5]

|  | G01M 7/08 |
· | Shock-testing [5]

P:30 |  | G01M 9/00 |
Aerodynamic testing; Arrangements in or on wind tunnels (building aspects section E; investigating properties of materials in general Fulltext... Hierarchy... Expanded...G01N)

|  | G01M 9/02 |
· | Wind tunnels [5]

|  | G01M 9/04 |
· · | Details [5]

|  | G01M 9/06 |
· | Measuring arrangements specially adapted for aerodynamic testing [5]

|  | G01M 9/08 |
· | Aerodynamic models [5]

P:40 |  | G01M 10/00 |
Hydrodynamic testing; Arrangements in or on ship-testing tanks or water tunnels (building aspects section E; investigating properties of materials in general Fulltext... Hierarchy... Expanded...G01N)

P:0 |  | G01M 11/00 |
Testing of optical apparatus; Testing structures by optical methods not otherwise provided for

|  | G01M 11/02 |
· | Testing of optical properties

|  | G01M 11/04 |
· · | Optical benches

|  | G01M 11/06 |
· · | Testing of alignment of vehicle head-light devices

|  | G01M 11/08 |
· | Testing of mechanical properties

P:70 |  | G01M 13/00 |
Testing of machine parts (investigating the cutting power of tools Fulltext... Hierarchy... Expanded...G01N, e.g. Fulltext... Hierarchy... Expanded...G01N 3/58)

|  | G01M 13/02 |
· | Testing of gearing or of transmission mechanisms (measuring efficiency Fulltext... Hierarchy... Expanded...G01L)

|  | G01M 13/04 |
· | Testing of bearings

P:80 |  | G01M 15/00 |
Testing of engines [4]

|  | G01M 15/02 |
· | Details or accessories of testing apparatus [8]

|  | G01M 15/04 |
· | Testing of internal-combustion engines, e.g. diagnostic testing of piston engines [8]

|  | G01M 15/05 |
· · | by combined monitoring of two or more different engine parameters [8]

|  | G01M 15/06 - G01M 15/12 |
Note(s) Group Fulltext... Hierarchy... Expanded...G01M 15/05 takes precedence over groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01M 15/06-G01M 15/12. [8]

|  | G01M 15/06 |
· · | by monitoring positions of pistons or cranks [8]

|  | G01M 15/08 |
· · | by monitoring pressure in cylinders [8]

|  | G01M 15/09 |
· · | by monitoring pressure in fluid ducts, e.g. in lubrication or cooling parts [8]

|  | G01M 15/10 |
· · | by monitoring exhaust gases [8]

|  | G01M 15/11 |
· · | by detecting misfire [8]

|  | G01M 15/12 |
· · | by monitoring vibrations [8]

|  | G01M 15/14 |
· | Testing of gas-turbine plants or jet-propulsion plants [8]

P:90 |  | G01M 17/00 |
Testing of vehicles (Fulltext... Hierarchy... Expanded...G01M 15/00 takes precedence; testing fluid tightness Fulltext... Hierarchy... Expanded...G01M 3/00; testing elastic properties of bodies or chassis, e.g. torsion-testing, Fulltext... Hierarchy... Expanded...G01M 5/00; testing alignment of vehicle head-lighting devices Fulltext... Hierarchy... Expanded...G01M 11/06)

|  | G01M 17/007 |
· | of wheeled or endless-tracked vehicles (Fulltext... Hierarchy... Expanded...G01M 17/08 takes precedence) [6]

|  | G01M 17/013 |
· · | of wheels [6]

|  | G01M 17/02 |
· · | of tyres [6]

|  | G01M 17/03 |
· · | of endless-tracks [6]

|  | G01M 17/04 |
· · | of suspension or of damping [6]

|  | G01M 17/06 |
· · | of steering behaviour; of rolling behaviour (measuring steering angles Fulltext... Hierarchy... Expanded...G01B; measuring steering forces Fulltext... Hierarchy... Expanded...G01L) [6]

|  | G01M 17/08 |
· | of railway vehicles [6]

|  | G01M 17/10 |
· · | of suspensions, axles or wheels [6]

P:100 |  | G01M 19/00 |
Testing of structures or of apparatus, not provided for in the other groups of this subclass

|  | G01M 19/02 |
· | Testing of sparking plugs (testing characteristics of the spark in internal-combustion engine ignition Fulltext... Hierarchy... Expanded...F02P 17/12; testing electric properties Fulltext... Hierarchy... Expanded...G01R 31/00)