PHOTOMETER WITH NON-DISPERSIVE INFRARED ABSORPTION SPECTROSCOPY (NDIR) FOR MEASURING SEVERAL CONSTITUENTS

摘要

The invention concerns a photometer for measuring gas constituents, having infrared radiation source with radiation emitter modulation, a measuring cell provided with a measurement and comparison chamber, and a sensor with optopneumatic absorption on the gas constituent X, therefore filled with X. In order to obtain accurate measurement of several constituents but requiring few appliances with such a photometer, at least another sensor is placed behind the first sensor, for measuring several gas constituents. Said other sensor is filled with the isotope of Y* for measuring the gas constituent Y and the first sensor is optically transparent as regards the other gas constituent Y* to be measured, in particular the absorption bands characteristic of said constituent.