Nondispersive infrared gas analyzer

摘要

A nondispersive infrared gas analyzer of the type wherein gas-filled chambers are arranged in the path of modulated infrared radiation. A measurement pickup is provided for producing a signal responsive to the response of a gas contained in the chamber to the infrared radiation. The infrared radiation is produced by a source of infrared radiation which is powered by a pulsed energy supply, the pulsed energy supply being responsive to control signals so as to provide pulses which have a duty cycle which is less than 1, and preferably between 0.1 and 0.5. The duration of the pulses is controlled in response to the maximum value of a measuring signal of an output of a measuring pickup. In other embodiments, the duration of the pulses may be determined empirically, by calculation, or by means of peak detector. This arrangement provides almost 100% modulation while considerably reducing power consumption and without loss of sensitivity. As such, the invention is particularly useful in battery-operated nondispersive infrared gas analyzer equipment adapted for field use.