Patent ID: 6843101
Filing Date: 2005-01-18
Classification: G01N,Y02A

Abstract:
1. A sensor for the measurement of carbon dioxide within a flow of air being input to at least one measuring cell ( 1 ) connected to at least one electroacoustic element ( 2 , 3 ) for transmitting and receiving airborne acoustic waves within said measuring cell ( 1 ) characterised in that at least one measuring signal is generated and being a monotonous function of the propagation velocity of said waves, and an indirect measure of said carbon dioxide concentration, said sensor including at least one automatic offset correction functionality for compensation of undesired offset variations of said measuring signal and wherein said offset correction functionality is based on the measurement or calculation of the average measuring signal, or extreme values calculated during a period of time, being shorter than the time lapses of said undesired offset variations.