BS IEC 62990-1:2019 pdf free.Workplace atmospheres — Gas detectors — Performance requirements of detectors for toxic gases.
diffusion equipment equipment in which the transfer of gas from the atmosphere to the sensor takes place withoutaspirated flow.
fixed equipment equipment fastened to a support, or otherwise secured in a specific location when energized.
portable equipment equipment intended to be carried by a person during its operation.
Note 1 to entry: Portable equipment is battery powered and includes, but is not limited to
a) hand-held equipment, typically less than 1 kg, which requires use of only one hand to operate,
b) personal monitors, similar in size and mass to the hand-held equipment, that are continuously operating whilethey are attached to the user, and
c) larger equipment that can be operated by the user while it is carried either by hand, by a shoulder strap or carrying harness and which may or may not have a hand directed probe.
transportable equipment equipment not intended to be carried by a person during operation，nor intended for fixedinstallation.
gas detection transmitter fixed gas detection equipment that provide a conditioned electronic signal or output indicationto a generally accepted industry standard (such as 4-20 mA), intended to be utilized withseparate gas detection control units or signal processing data acquisition, central monitoring and similar systems,which typically process information from various locations and sources including, but not limited to gas detection equipment.
gas detection control unit equipment intended to provide display indication, alarm functions， output contacts or alarmsignal outputs or any combination when operated with remote sensor(s)
separate gas detection control unit equipment intended to provide display indication, alarm functions,output contacts or alarmsignal outputs or any combination when operated with gas detection transmitter(s)
equipment with integral sensor(s) equipment that provides display indication，alarm functions，output contacts and/or alarmsignal outputs using a sensor which is within or directly assembled to the equipment housing.
accessory component which can be fitted to the equipment for special purpose.
EXAMPLE: External gas pump, sampling probe, hoses, collecting cone, weather protection device.
adjustment procedure carried out to minimize the deviation of the measured value from the test gasconcentration.
Note 1 to entry: When the equipment is adjusted to give an indication of zero in clean air,the procedure iscalled ‘zero adjustment’.
calibration procedure which establishes the relationship between a measured value and theconcentration of a test gas.
Note 1 to entry: lf the deviation at calibration is too high, usually an adjustment will be carried out subsequently.
field calibration kit means of presenting test gas to the equipment for the purpose of calibrating,adjusting orverifying the operation of the equipment.BS IEC 62990-1 pdf download.