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 subclass covers also means for identifying or incapacitating burglars or the like.
This subclass does not cover:
the mere provision of an audible or visible signalling device on measuring or switching apparatus;
alarm systems for indicating that a specific variable has exceeded, or fallen below, a predetermined value, which are covered by the relevant subclasses of class Fulltext... Hierarchy... Expanded...G01 for the measurement of that variable.
alarms for specific processes or types of machines or apparatus, which are covered by the relevant subclasses for the processes, machines, or apparatus.
In this subclass, the following term is used with the meaning indicated:
"systems" may cover also devices peculiar thereto.
using hydraulic transmission; using pneumatic transmission
G08B 7/06
·
using electric transmission
G08B 7/08
·
using explosives
G08B 9/00
Order telegraph apparatus, i.e. means for transmitting one of a finite number of different orders at the discretion of the user, e.g. bridge to engine room orders in ships (signalling devices in mines Fulltext... Hierarchy... Expanded...E21F 17/18)
G08B 9/02
·
Details
G08B 9/04
· ·
Means for recording operation of the apparatus
G08B 9/06
· ·
Means for indicating disagreement between orders given and those carried out
by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind
G08B 13/10
· ·
by pressure on floors, floor coverings, stair treads, counters, or tills
G08B 13/12
· ·
by the breaking or disturbance of stretched cords or wires
G08B 13/14
· ·
by lifting or attempted removal of hand-portable articles
G08B 13/16
·
Actuation by interference with mechanical vibrations in air or other fluid
G08B 13/18
·
Actuation by interference with heat, light, or radiation of shorter wavelength; Actuation by intruding sources of heat, light, or radiation of shorter wavelength
by interference with electromagnetic field distribution
G08B 13/26
· ·
by proximity of an intruder causing variation in capacitance or inductance of a circuit
G08B 15/00
Identifying, scaring, or incapacitating burglars, thieves, or intruders, e.g. by explosives (burglar traps, or the like, on safes Fulltext... Hierarchy... Expanded...E05G 5/02)
G08B 15/02
·
with smoke, gas, or coloured or odorous powder or liquid
Constructional details (discharge tubes for measuring pressure of introduced gas, or for detecting presence of gas, in general Fulltext... Hierarchy... Expanded...H01J 41/02) [5]
indicating a condition of sleep, e.g. anti-dozing alarms (safety devices for propulsion-unit control of vehicles responsive to incapacity of driver Fulltext... Hierarchy... Expanded...B60K 28/06) [7]
G08B 21/08
· ·
responsive to the presence of persons in a body of water, e.g. a swimming pool; responsive to an abnormal condition of a body of water [7]