|  | 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

|  | G12 |
INSTRUMENT DETAILS

|  | G12B |
DETAILS OF INSTRUMENTS, OR COMPARABLE DETAILS OF OTHER APPARATUS, NOT OTHERWISE PROVIDED FOR

|  | G12B |
Note(s) This subclass covers only details which are not restricted to measuring instruments or to any other apparatus covered by a single class. This subclass does not cover: details covered by any other subclass in section A, F, G or H. In particular, details restricted to the measuring instruments are covered by the relevant subclasses of class Fulltext... Hierarchy... Expanded...G01, e.g. Fulltext... Hierarchy... Expanded...G01D; constructional details restricted to electric apparatus, e.g. casings, screenings, which are covered by subclass Fulltext... Hierarchy... Expanded...H05K or the relevant subclass in section H. Attention is drawn to the Notes following the title of section G, especially as regards to the definition of the term "measuring" in Note (2) following the title of class Fulltext... Hierarchy... Expanded...G01.

|  | G12B |
Subclass index
SENSITIVE ELEMENTS PRODUCING MOVEMENT OR DISPLACEMENT; DETAILS OF MOVEMENTS | 1/00; 3/00
ADJUSTING POSITION OR ATTITUDE; COMPENSATING FOR TEMPERATURE EFFECTS | 5/00; 7/00
HOUSING, SUPPORTING; INDICATING ELEMENTS | 9/00; 11/00
CALIBRATING | 13/00
COOLING; SCREENING | 15/00; 17/00

|  | G12B 1/00 |
Sensitive elements capable of producing movement or displacement for purposes not limited to measurement; Associated transmission mechanisms therefor

|  | G12B 1/02 |
· | Compound strips or plates, e.g. bimetallic (thermometers using bimetallic elements Fulltext... Hierarchy... Expanded...G01K 5/62)

|  | G12B 1/04 |
· | Hollow bodies having parts which are deformable or displaceable under pressure, e.g. Bourdon tube, bellows (bellows in general Fulltext... Hierarchy... Expanded...F16J 3/00)

|  | G12B 3/00 |
Details of movements not otherwise provided for (damping of shock or vibrations in general Fulltext... Hierarchy... Expanded...F16F; avoiding out-of-balance forces Fulltext... Hierarchy... Expanded...F16F 15/00; testing balance Fulltext... Hierarchy... Expanded...G01M)

|  | G12B 3/02 |
· | Caging of movements, i.e. locking of movements when not in use

|  | G12B 3/04 |
· | Suspensions (bearings Fulltext... Hierarchy... Expanded...F16C)

|  | G12B 3/06 |
· | Reducing effects of friction, e.g. by vibration (by lubrication Fulltext... Hierarchy... Expanded...F16N)

|  | G12B 3/08 |
· | Damping of movements, e.g. to promote rapid non-oscillatory movement to a final reading

|  | G12B 3/10 |
· · | using eddy currents

|  | G12B 5/00 |
Adjusting position or attitude, e.g. level, of instruments or other apparatus, or of parts thereof (levels per se Fulltext... Hierarchy... Expanded...G01C 9/00); Compensating for the effects of tilting or acceleration, e.g. for optical apparatus

|  | G12B 7/00 |
Compensating for the effects of temperature (by cooling Fulltext... Hierarchy... Expanded...G12B 15/00)

|  | G12B 9/00 |
Housing or supporting of instruments or other apparatus

|  | G12B 9/02 |
· | Casings; Housings; Cabinets (sealing arrangements for transmission members Fulltext... Hierarchy... Expanded...F16J, particularly Fulltext... Hierarchy... Expanded...F16J 15/50)

|  | G12B 9/04 |
· · | Details, e.g. cover

|  | G12B 9/06 |
· · · | Metal casings

|  | G12B 9/08 |
· | Supports; Devices for carrying

|  | G12B 9/10 |
· · | Instrument boards; Panels; Desks; Racks; Frameworks

|  | G12B 11/00 |
Indicating elements; Illumination thereof

|  | G12B 11/02 |
· | Scales; Dials

|  | G12B 11/04 |
· | Pointers; Setting-mechanisms therefor

|  | G12B 13/00 |
Calibrating of instruments or apparatus (calibrating of measuring instruments Fulltext... Hierarchy... Expanded...G01)

|  | G12B 15/00 |
Cooling (by refrigeration, e.g. circulation of refrigerated fluid, Fulltext... Hierarchy... Expanded...F25D; heat-exchange or heat-transfer details of general application Fulltext... Hierarchy... Expanded...F28F)

|  | G12B 15/02 |
· | by closed-cycle fluid-circulating systems

|  | G12B 15/04 |
· | by currents of fluid, e.g. air, in open cycle

|  | G12B 15/06 |
· | by contact with heat-absorbing or radiating masses, e.g. heat-sink

|  | G12B 17/00 |
Screening (insulation or other protection of buildings Fulltext... Hierarchy... Expanded...E04B; emergency protection of apparatus in general Fulltext... Hierarchy... Expanded...F16P 7/00; in connection with acoustic waves Fulltext... Hierarchy... Expanded...G10K 11/00; in connection with nuclear radiation Fulltext... Hierarchy... Expanded...G21F)

|  | G12B 17/00 |
Note(s) This group covers: the protection of instruments or other apparatus from external radiation or other influences; the prevention of the emission of undesirable radiation or other influences by instruments or other apparatus.

|  | G12B 17/02 |
· | from electric or magnetic fields, e.g. radio waves

|  | G12B 17/04 |
· | from ultra-violet, visible, or infra-red light (screening of lighting devices Fulltext... Hierarchy... Expanded...F21V; optical filters Fulltext... Hierarchy... Expanded...G02B 5/20)

|  | G12B 17/06 |
· | from heat (Fulltext... Hierarchy... Expanded...G12B 17/04 takes precedence; cooling Fulltext... Hierarchy... Expanded...G12B 15/00)

|  | G12B 17/08 |
· | from influences producing mechanical damage, e.g. caused by blast, by external object, by person (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G12B 17/02-G12B 17/06 take precedence)