Patent ID: 6042634
Filing Date: 2000-03-28
Classification: G01N

Abstract:
A method of sampling gas obtained from a stream of products of combustion, the method comprising the steps of:(a) obtaining a sample of gas from a stream of products of combustion;(b) urging the sample of gas through a sample dryer tube disposed inside a purge gas tube;(c) urging a purge gas through a space formed between the purge gas tube and the sample dryer tube in a direction opposite the sample of gas in the sample dryer tube;(d) maintaining the sample dryer tube adjacent an end thereof which receives the sample of gas therein one of at and above a temperature above the dew point temperature of water in the sample of gas; and(e) sensing a constituent in the sample of gas exhausted from the sample dryer tube, wherein:the purge gas entering the space contains less water vapor than the sample of gas entering the sample dryer tube; andthe sample dryer tube is formed at least in part from a hydrophilic membrane which enables water vapor to be conveyed from the sample of gas to the purge gas whereby the purge gas exhausted from the sample dryer tube contains more water vapor than the purge gas entering the space, and the sample of gas exhausted from the space contains less water vapor than the sample of gas entering the sample dryer tube.