Non-dispersion infrared analyzer for gas and vapor uses switch interlaced pulse- and chopper-mode measurements

摘要

Gas and vapor concentrations are determined by a non-dispersing IR analyzer where the infrared source is modulated, with short impulses in pulse-mode and short time intervals in chopper-mode, and where the duration of IR source pulses are the same, or shorter than the time-constant for the pyro-electric sensor and the chopper frequency of the IR source lies between the thermal frequency and angular electrical frequency of the pyro-electric sensor.