Patent ID: 6037592
Filing Date: 2000-03-14
Classification: G01N

Abstract:
A sensor system for measuring the concentration of gas dissolved in a liquid, the gas comprising one or more constituent gases in a distribution, the system comprising:a. a passive extractor which extracts dissolved gas from the gas-containing liquid, there being a known relationship between the concentration of a constituent gas in the extracted gas and the concentration of the constituent gas remaining dissolved in the gas-containing liquid; andb. a gas sensor which senses the concentration of a constituent gas in the extracted gas, in the presence of other constituent gases, the gas sensor comprising(1) a sample chamber having plural tubes which receive the extracted gas,(2) a non-dispersive infrared (IR) absorption sensing system which generates an electrical signal corresponding to the light absorption, at one or more specified IR wavelengths, of the extracted gas in the chamber, and(3) an electrical output comprising the electrical signal generated by the non-dispersive IR absorption sensing system comprising a respective IR emitter disposed at one end of a respective tube, each IR emitter comprising a blackbody source for emitting IR light with wavelengths in the range 2.5 to 15 .mu.m, a filter for limiting the IR light transmitted in each tube to a respective sub-range of wavelengths, and plural IR detectors disposed at an opposite end of each of said tubes for receiving the light transmitted in said tube to produce an electrical output signal as a function of the intensity of the received light, each IR detector being tuned to a predetermined wavelength in said respective sub-range corresponding to a respective one of said constituent gases to produce a detection signal representing the presence of said one constituent gas if IR light at said predetermined wavelength is of reduced intensity.