Definition(s)
Time of Response, t(x), (not applicable to spot-reading apparatus) (times)
Time interval, with the apparatus in a warmed-up condition, between the time when an instantaneous change between clean air and the standard test gas, or vice versa, is produced at the apparatus inlet, and the time when the response reaches a stated percentage (x) of the stabilised signal on the standard test gas.
Source: IEC 60079-29-1, Explosive atmospheres – Part 29-1: Gas detectors – Performance requirements of detectors for flammable gases. Global Standards