Dinitrogen tetroxide detection and estimation - by increase in electrical resistance when gas passes through graphite powder

摘要

A method and appts for detecting or estimating N2O4 in air or combustion products passing through a compressed bed of powdered graphite, by the resultant increase of electrical resistance. After one minutes flow as little as 1 ppm N2O4 may be positively detected in presence of 40 ppm SO2 and without interference by humidity. A similar method is used for detection of fluorine. The signal may be amplified, and used to operate an alarm, in pollution control system, or the method may be used for quantitative analysis, or for study of gas/solid adsorption.