|  | 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 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.

|  | G01T |
MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry Fulltext... Hierarchy... Expanded...G01N; counters per se Fulltext... Hierarchy... Expanded...G06M, Fulltext... Hierarchy... Expanded...H03K; electric discharge tubes for analysing radiation or particles Fulltext... Hierarchy... Expanded...H01J 40/00, Fulltext... Hierarchy... Expanded...H01J 47/00, Fulltext... Hierarchy... Expanded...H01J 49/00)

|  | G01T |
Note(s) This subclass covers the measurement of X-radiation, gamma radiation, corpuscular radiation, cosmic radiation, or neutron radiation. Attention is drawn to the Notes following the title of class Fulltext... Hierarchy... Expanded...G01.

|  | G01T 1/00 |
Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation (Fulltext... Hierarchy... Expanded...G01T 3/00, Fulltext... Hierarchy... Expanded...G01T 5/00 take precedence) [2]

|  | G01T 1/02 |
· | Dosimeters (Fulltext... Hierarchy... Expanded...G01T 1/15 takes precedence; measuring exposure time to X-rays Fulltext... Hierarchy... Expanded...H05G 1/28) [2]

|  | G01T 1/04 |
· · | Chemical dosimeters (Fulltext... Hierarchy... Expanded...G01T 1/06, Fulltext... Hierarchy... Expanded...G01T 1/08 take precedence)

|  | G01T 1/06 |
· · | Glass dosimeters

|  | G01T 1/08 |
· · | Photographic dosimeters (photosensitive materials or processes for photographic purposes Fulltext... Hierarchy... Expanded...G03C)

|  | G01T 1/10 |
· · | Luminescent dosimeters

|  | G01T 1/105 |
· · · | Read-out devices (Fulltext... Hierarchy... Expanded...G01T 1/115 takes precedence) [2]

|  | G01T 1/11 |
· · · | Thermo-luminescent dosimeters

|  | G01T 1/115 |
· · · · | Read-out devices [2]

|  | G01T 1/12 |
· · | Calorimetric dosimeters

|  | G01T 1/14 |
· · | Electrostatic dosimeters (construction of ionisation chambers Fulltext... Hierarchy... Expanded...H01J 47/02)

|  | G01T 1/142 |
· · · | Charging devices; Read-out devices [2]

|  | G01T 1/15 |
· | Instruments in which pulses generated by a radiation detector are integrated, e.g. by a diode pump circuit (pulse rate meters in general Fulltext... Hierarchy... Expanded...G01R 23/02)

|  | G01T 1/16 |
· | Measuring radiation intensity (Fulltext... Hierarchy... Expanded...G01T 1/29 takes precedence) [2]

|  | G01T 1/161 |
· · | Applications in the field of nuclear medicine, e.g. in vivo counting (applying radioactive material to the body Fulltext... Hierarchy... Expanded...A61M 36/00) [2]

|  | G01T 1/163 |
· · · | Whole-body counters [2]

|  | G01T 1/164 |
· · · | Scintigraphy (radio isotopes Fulltext... Hierarchy... Expanded...G21G 4/00; tracers Fulltext... Hierarchy... Expanded...G21H 5/00) [2]

|  | G01T 1/166 |
· · · · | involving relative movement between detector and subject [2]

|  | G01T 1/167 |
· · | Measuring radioactive content of objects, e.g. contamination (whole-body counters Fulltext... Hierarchy... Expanded...G01T 1/163) [2]

|  | G01T 1/169 |
· · | Exploration, location of contaminated surface areas (prospecting by the use of nuclear radiation, natural or induced Fulltext... Hierarchy... Expanded...G01V 5/00) [2]

|  | G01T 1/17 |
· · | Circuit arrangements not adapted to a particular type of detector

|  | G01T 1/172 |
· · · | with coincidence circuit arrangements (Fulltext... Hierarchy... Expanded...G01T 1/178 takes precedence) [2]

|  | G01T 1/175 |
· · · | Power supply circuits (converters Fulltext... Hierarchy... Expanded...H02M) [2]

|  | G01T 1/178 |
· · · | for measuring specific activity in the presence of other radioactive substances, e.g. natural, in the air or in liquids such as rain-water [2]

|  | G01T 1/18 |
· · | with counting-tube arrangements, e.g. with Geiger counters (tubes Fulltext... Hierarchy... Expanded...H01J 47/00)

|  | G01T 1/185 |
· · | with ionisation-chamber arrangements (construction of ionisation chambers Fulltext... Hierarchy... Expanded...H01J 47/02) [2]

|  | G01T 1/20 |
· · | with scintillation detectors

|  | G01T 1/202 |
· · · | the detector being a crystal

|  | G01T 1/203 |
· · · | the detector being made of plastics

|  | G01T 1/204 |
· · · | the detector being a liquid

|  | G01T 1/205 |
· · · | the detector being a gas

|  | G01T 1/208 |
· · · | Circuits specially adapted for scintillation detectors, e.g. for the photo-multiplier section [2]

|  | G01T 1/22 |
· · | with Cerenkov detectors

|  | G01T 1/24 |
· · | with semiconductor detectors (semiconductor detectors per se Fulltext... Hierarchy... Expanded...H01L 31/00)

|  | G01T 1/26 |
· · | with resistance detectors

|  | G01T 1/28 |
· · | with secondary-emission detectors (secondary-electron-emitting electrodes in general Fulltext... Hierarchy... Expanded...H01J 1/32)

|  | G01T 1/29 |
· | Measurement performed on radiation beams, e.g. position or section of the beam; Measurement of spatial distribution of radiation (scintigraphy Fulltext... Hierarchy... Expanded...G01T 1/164; mass-spectrometers Fulltext... Hierarchy... Expanded...H01J 49/00) [2]

|  | G01T 1/30 |
· | Measuring half-life of a radioactive substance

|  | G01T 1/32 |
· | Measuring polarisation of particles

|  | G01T 1/34 |
· | Measuring cross-section, e.g. absorption cross-section of particles

|  | G01T 1/36 |
· | Measuring spectral distribution of X-rays or of nuclear radiation

|  | G01T 1/38 |
· · | Particle discrimination and measurement of relative mass, e.g. by measurement of loss of energy with distance (dE/dx) [2]

|  | G01T 1/40 |
· · | Stabilisation of spectrometers [2]

|  | G01T 3/00 |
Measuring neutron radiation (Fulltext... Hierarchy... Expanded...G01T 5/00 takes precedence) [2]

|  | G01T 3/02 |
· | by shielding other radiation

|  | G01T 3/04 |
· | using calorimetric devices

|  | G01T 3/06 |
· | with scintillation detectors [2]

|  | G01T 3/08 |
· | with semiconductor detectors (semiconductor detectors per se Fulltext... Hierarchy... Expanded...H01L 31/00) [2]

|  | G01T 5/00 |
Recording of movements or tracks of particles (spark chambers Fulltext... Hierarchy... Expanded...H01J 47/00); Processing or analysis of such tracks [2]

|  | G01T 5/02 |
· | Processing of tracks; Analysis of tracks

|  | G01T 5/04 |
· | Cloud chambers, e.g. Wilson chamber

|  | G01T 5/06 |
· | Bubble chambers

|  | G01T 5/08 |
· | Scintillation chambers (discharge tubes Fulltext... Hierarchy... Expanded...H01J 40/00, Fulltext... Hierarchy... Expanded...H01J 47/00; semiconductor devices Fulltext... Hierarchy... Expanded...H01L)

|  | G01T 5/10 |
· | Plates or blocks in which tracks of nuclear particles are made visible by after-treatment, e.g. using photographic emulsion, using mica

|  | G01T 5/12 |
· | Circuit arrangements with multi-wire or parallel-plate chambers, e.g. spark chambers (tubes per se Fulltext... Hierarchy... Expanded...H01J 47/00) [2]

|  | G01T 7/00 |
Details of radiation-measuring instruments

|  | G01T 7/02 |
· | Collecting-means for receiving or storing samples to be investigated

|  | G01T 7/04 |
· · | by filtration

|  | G01T 7/06 |
· · | by electrostatic precipitation (Fulltext... Hierarchy... Expanded...G01T 7/04 takes precedence)

|  | G01T 7/08 |
· | Means for conveying samples received

|  | G01T 7/10 |
· · | using turntables

|  | G01T 7/12 |
· | Provision for actuation of an alarm