MULTICHANNEL INFRARED GAS ANALYSER WITH POSITION ADJUSTMENT OF DIODE EMITTERS AND RECEIVERS Russian patent published in 2025 - IPC G01N21/3504 

FIELD: measuring equipment.

SUBSTANCE: disclosed are infrared gas analysers based on an open or closed optical cell. In the open version, the infrared absorption gas analyser comprises an electronic unit, at least two optical radiation transmitter-receiver pairs and a spherical mirror. At that, each transmitter-receiver pair crystals radiating and receiving surfaces are located on the mirror in the mirror objects/images plane located at a distance equal to double the mirror focal distance, spectral absorption band of each transmitter-receiver pair is provided by the selection of light-emitting diodes and photodiodes in such a way that their spectral characteristic (radiation spectrum of the transmitter and sensitivity of the photodetector) falls into the absorption band of the gas to be determined and does not overlap with the absorption bands of other gases, each transmitter and receiver is mounted in a separate holder which simultaneously serves as a adjusting device for accurate alignment of the image of the emitting region of the LED on the surface of the light-sensitive region of the photodiode since it has the required degree of freedom and is fixed by a pressure screw.

EFFECT: simultaneous measurement of several absorbing (greenhouse) gases in the air is achieved, including water vapour, which is necessary in climatic applications, since relative concentrations for dry air are usually used, and in order to convert to dry air, it is necessary to simultaneously measure water vapour content; using present gas analyser design can measure "dry" content of gases such as carbon dioxide (CO₂), methane (CH₄), carbon monoxide (CO), nitrogen oxides.

14 cl, 7 dwg