A DEVICE FOR MEASURING THE CONCENTRATION OF CARBON DIOXIDE IN A GAS

摘要

A device for quantitatively measuring CO2 in a gas mixture, such as air, comprises an indicator unit (23) including a CO2 indicating element (26) whose ability to return incident light varies with the CO2 concentration of a gas contacting the indicating element, a light source (18, 19) for illuminating the indicating element, and photoelectric light measuring means (21) for measuring the intensity of light returned from the indicating element upon illumination thereof by the light source. The indicator unit (23) includes a cavity (23A) receptive of one end of a light guide (15, 17), one end of which is optically coupled to the indicating element (26) and the opposite end of which is optically coupled to the light source (18, 19) and to the light measuring means (21).