|  | 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.

|  | G01P |
MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow Fulltext... Hierarchy... Expanded...A61B 5/02, Fulltext... Hierarchy... Expanded...A61B 8/06; monitoring speed or deceleration of electrically-propelled vehicles Fulltext... Hierarchy... Expanded...B60L 3/00; vehicle lighting systems adapted to indicate speed Fulltext... Hierarchy... Expanded...B60Q 1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying Fulltext... Hierarchy... Expanded...G01C; combined measuring devices for measuring two or more variables of movement Fulltext... Hierarchy... Expanded...G01C 23/00; measuring velocity of sound Fulltext... Hierarchy... Expanded...G01H; measuring velocity of light Fulltext... Hierarchy... Expanded...G01J 7/00; determining direction or velocity of solid objects by reflection or reradiation of radio or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, Fulltext... Hierarchy... Expanded...G01S; measuring speed of nuclear radiation Fulltext... Hierarchy... Expanded...G01T; measuring acceleration of gravity Fulltext... Hierarchy... Expanded...G01V)

|  | G01P |
Note(s) This subclass covers measuring direction or velocity of flowing fluids using propagation effects of radiowaves or other waves caused in the fluid itself, e.g. by laser anemometer, by ultrasonic flowmeter with "sing-around-system". [4] Attention is drawn to the Notes following the title of class Fulltext... Hierarchy... Expanded...G01.

|  | G01P |
Subclass index
INDICATING MOVEMENT OR DIRECTION OF MOVEMENT | 13/00
MEASURING LINEAR OR ANGULAR SPEED OF SOLID BODIES |
Characterised by prevailing principle of action of the means | 3/00
By integration; by gyroscopic effect; by averaging | 7/00; 9/00; 11/00
MEASURING SPEED OF FLUIDS OR RELATIVE SPEED OF SOLID TO FLUID OR FLUID TO SOLID | 5/00
MEASURING ACCELERATION OR SUDDEN CHANGE OF ACCELERATION | 15/00
DETAILS | 1/00
FUNCTIONAL TESTING OR CALIBRATING | 21/00

|  | G01P 1/00 |
Details of instruments

|  | G01P 1/02 |
· | Housings

|  | G01P 1/04 |
· | Special adaptations of driving means

|  | G01P 1/07 |
· | Indicating devices, e.g. for remote indication (indicating working conditions of vehicles Fulltext... Hierarchy... Expanded...G07C 5/00) [3]

|  | G01P 1/08 |
· · | Arrangements of scales, pointers, lamps, or acoustic indicators, e.g. in automobile speedometers

|  | G01P 1/10 |
· · · | for indicating predetermined speeds

|  | G01P 1/11 |
· · · · | by the detection of the position of the indicator needle [3]

|  | G01P 1/12 |
· | Recording devices (registering working conditions of vehicles Fulltext... Hierarchy... Expanded...G07C 5/00) [3]

|  | G01P 1/14 |
· · | for permanent recording [3]

|  | G01P 1/16 |
· · | for erasable recording, e.g. magnetic recording [3]

|  | G01P 3/00 |
Measuring linear or angular speed; Measuring differences of linear or angular speeds (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G01P 5/00-G01P 11/00 take precedence; counting mechanisms Fulltext... Hierarchy... Expanded...G06M)

|  | G01P 3/00 |
Note(s) The subgroups of this main group are distinguished by the method of measurement which is of major importance. Thus the mere application of other methods for giving a final indication does not affect the classification.

|  | G01P 3/02 |
· | Devices characterised by the use of mechanical means

|  | G01P 3/04 |
· · | by comparing two speeds

|  | G01P 3/06 |
· · · | using a friction gear

|  | G01P 3/08 |
· · · | using differential gearing

|  | G01P 3/10 |
· · | by actuating an indicating element, e.g. pointer, for a fixed time

|  | G01P 3/12 |
· · | by making use of a system excited by impact

|  | G01P 3/14 |
· · | by exciting one or more mechanical resonance systems

|  | G01P 3/16 |
· · | by using centrifugal forces of solid masses (governors Fulltext... Hierarchy... Expanded...G05D 13/00)

|  | G01P 3/18 |
· · · | transferred to the indicator by mechanical means

|  | G01P 3/20 |
· · · | transferred to the indicator by fluid means

|  | G01P 3/22 |
· · · | transferred to the indicator by electric or magnetic means

|  | G01P 3/24 |
· · | by using friction effects (Fulltext... Hierarchy... Expanded...G01P 3/06 takes precedence)

|  | G01P 3/26 |
· | Devices characterised by the use of fluids

|  | G01P 3/28 |
· · | by using pumps

|  | G01P 3/30 |
· · | by using centrifugal forces of fluids

|  | G01P 3/32 |
· · · | in a rotary container communicating with a fixed container

|  | G01P 3/34 |
· · | by using friction effects

|  | G01P 3/36 |
· | Devices characterised by the use of optical means, e.g. using infra-red, visible, or ultra-violet light (Fulltext... Hierarchy... Expanded...G01P 3/68 takes precedence; gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams, Fulltext... Hierarchy... Expanded...G01C 19/64)

|  | G01P 3/38 |
· · | using photographic means

|  | G01P 3/40 |
· · | using stroboscopic means

|  | G01P 3/42 |
· | Devices characterised by the use of electric or magnetic means (Fulltext... Hierarchy... Expanded...G01P 3/66 takes precedence; measuring electric or magnetic values in general Fulltext... Hierarchy... Expanded...G01R)

|  | G01P 3/44 |
· · | for measuring angular speed (Fulltext... Hierarchy... Expanded...G01P 3/56 takes precedence)

|  | G01P 3/46 |
· · · | by measuring amplitude of generated current or voltage

|  | G01P 3/48 |
· · · | by measuring frequency of generated current or voltage

|  | G01P 3/481 |
· · · · | of pulse signals [3]

|  | G01P 3/482 |
· · · · · | delivered by nuclear radiation detectors [3]

|  | G01P 3/483 |
· · · · · | delivered by variable capacitance detectors [3]

|  | G01P 3/484 |
· · · · · | delivered by contact-making switches [3]

|  | G01P 3/486 |
· · · · · | delivered by photo-electric detectors [3]

|  | G01P 3/487 |
· · · · · | delivered by rotating magnets [3]

|  | G01P 3/488 |
· · · · · | delivered by variable reluctance detectors [3]

|  | G01P 3/489 |
· · · · · | Digital circuits therefor [3]

|  | G01P 3/49 |
· · · | using eddy currents

|  | G01P 3/495 |
· · · · | where the indicating means responds to forces produced by the eddy currents and the generating magnetic field [3]

|  | G01P 3/50 |
· · | for measuring linear speed (Fulltext... Hierarchy... Expanded...G01P 3/56 takes precedence)

|  | G01P 3/52 |
· · · | by measuring amplitude of generated current or voltage

|  | G01P 3/54 |
· · · | by measuring frequency of generated current or voltage

|  | G01P 3/56 |
· · | for comparing two speeds

|  | G01P 3/58 |
· · · | by measuring or comparing amplitudes of generated currents or voltages

|  | G01P 3/60 |
· · · | by measuring or comparing frequency of generated currents or voltages

|  | G01P 3/62 |
· | Devices characterised by the determination of the variation of atmospheric pressure with height to measure the vertical components of speed (measuring pressure in general Fulltext... Hierarchy... Expanded...G01L)

|  | G01P 3/64 |
· | Devices characterised by the determination of the time taken to traverse a fixed distance

|  | G01P 3/66 |
· · | using electric or magnetic means (Fulltext... Hierarchy... Expanded...G01P 3/80 takes precedence; measuring short time intervals Fulltext... Hierarchy... Expanded...G04F) [4]

|  | G01P 3/68 |
· · | using optical means, i.e. using infra-red, visible, or ultra-violet light (Fulltext... Hierarchy... Expanded...G01P 3/80 takes precedence) [4]

|  | G01P 3/80 |
· · | using auto-correlation or cross-correlation detection means [4]

|  | G01P 5/00 |
Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft (application of speed-measuring devices for measuring volume of fluids Fulltext... Hierarchy... Expanded...G01F)

|  | G01P 5/01 |
· | by using swirlflowmeter [3]

|  | G01P 5/02 |
· | by measuring forces exerted by the fluid on solid bodies, e.g. anemometer

|  | G01P 5/04 |
· · | using deflection of baffle-plates

|  | G01P 5/06 |
· · | using rotation of vanes (measuring speed of rotating shafts Fulltext... Hierarchy... Expanded...G01P 3/00)

|  | G01P 5/07 |
· · · | with electrical coupling to the indicating device [3]

|  | G01P 5/08 |
· | by measuring variation of an electric variable directly affected by the flow, e.g. by using dynamo-electric effect

|  | G01P 5/10 |
· | by measuring thermal variables

|  | G01P 5/12 |
· · | using variation of resistance of a heated conductor

|  | G01P 5/14 |
· | by measuring differences of pressure in the fluid

|  | G01P 5/16 |
· · | using Pitot tubes

|  | G01P 5/165 |
· · · | Arrangements or constructions of Pitot tubes [3]

|  | G01P 5/17 |
· · · | Coupling arrangements to the indicating device [3]

|  | G01P 5/175 |
· · · · | with the determination of Mach number (analogue computers therefor Fulltext... Hierarchy... Expanded...G06G 7/57) [3]

|  | G01P 5/18 |
· | by measuring the time taken to traverse a fixed distance

|  | G01P 5/20 |
· · | using particles entrained by a fluid stream (Fulltext... Hierarchy... Expanded...G01P 5/22 takes precedence) [4]

|  | G01P 5/22 |
· · | using auto-correlation or cross-correlation detection means [4]

|  | G01P 7/00 |
Measuring speed by integrating acceleration (measuring travelled distance by double integration of acceleration Fulltext... Hierarchy... Expanded...G01C 21/16)

|  | G01P 9/00 |
Measuring speed by using gyroscopic effect, e.g. using gas, using electron beam (gyroscopes or turn-sensitive devices per se Fulltext... Hierarchy... Expanded...G01C 19/00)

|  | G01P 9/02 |
· | using rotary gyroscopes

|  | G01P 9/04 |
· | using turn-sensitive devices with vibrating masses, e.g. tuning-fork

|  | G01P 11/00 |
Measuring average value of speed (by determining time taken to traverse a fixed distance Fulltext... Hierarchy... Expanded...G01P 3/64, Fulltext... Hierarchy... Expanded...G01P 5/18)

|  | G01P 11/02 |
· | Measuring average speed of a number of bodies, e.g. of vehicles for traffic control

|  | G01P 13/00 |
Indicating or recording presence, absence, or direction, of movement (counting moving objects Fulltext... Hierarchy... Expanded...G06M 7/00; electric switches Fulltext... Hierarchy... Expanded...H01H)

|  | G01P 13/02 |
· | Indicating direction only, e.g. by weather vane

|  | G01P 13/04 |
· · | Indicating positive or negative direction of a linear movement or clockwise or anti-clockwise direction of a rotational movement [3]

|  | G01P 15/00 |
Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration

|  | G01P 15/02 |
· | by making use of inertia forces (Fulltext... Hierarchy... Expanded...G01P 15/14 takes precedence)

|  | G01P 15/03 |
· · | by using non-electrical means [3]

|  | G01P 15/04 |
· · | for indicating maximum value

|  | G01P 15/06 |
· · · | using members subjected to a permanent deformation

|  | G01P 15/08 |
· · | with conversion into electric or magnetic values

|  | G01P 15/09 |
· · · | by piezo-electric pick-up [3]

|  | G01P 15/10 |
· · · | by vibratory strings

|  | G01P 15/11 |
· · · | by inductive pick-up [3]

|  | G01P 15/12 |
· · · | by alteration of electrical resistance

|  | G01P 15/125 |
· · · | by capacitive pick-up [3]

|  | G01P 15/13 |
· · · | by measuring the force required to restore a proofmass subjected to inertial forces to a null position [3]

|  | G01P 15/135 |
· · · | by making use of contacts which are actuated by a movable inertial mass [3]

|  | G01P 15/14 |
· | by making use of gyroscopes (gyroscopes per se Fulltext... Hierarchy... Expanded...G01C 19/00)

|  | G01P 15/16 |
· | by evaluating the time-derivative of a measured speed signal [3]

|  | G01P 21/00 |
Testing or calibrating of apparatus or devices covered by the preceding groups

|  | G01P 21/02 |
· | of speedometers