System for measuring the concentration of a gas

摘要

The application relates to a system for continuously measuring the concentration of a multiatomic, nonelemental gas using a nondispersive infrared single-beam photometer. The alternating light beam originating from a switched radiation source passes through an absorption cell with the gas to be measured flowing through it and simultaneously strikes two photoreceivers. One of the photoreceivers has a filter in front of it. The ratio is taken of the rectified output signals from the two photoreceivers and, since this is a measure of the concentration of the gas, it is fed to a measured-value indicator.