The effect of extreme humidity and temperature on gas detector tube performance.
McCammon-CS; Crouse-WE; Carroll-HB
Am Ind Hyg Assoc J 1982 Jan; 43(1):18-25
NIOSH investigated the effect of humidity and temperature on gas detector tubes tested at two concentrations (the current OSHA standard and 2 times the standard). Two brands of detectors used by the Bureau of Mines from four different manufacturers were tested with carbon-monoxide (630080), carbon-dioxide (124389), nitric-oxide (10102439), nitrogen-dioxide (10102440), sulfur-dioxide (7446095), hydrogen-sulfide (7783064), and formaldehyde (50000). Five replicate samples of each tube were tested. Testing temperatures varied from 40 to 120 degrees F; relative humidities were varied from 20 to 90 percent. A premeation tube system was used for accurate production of atmospheres containing the desired contaminants. Each tube was read by three different observers. An analysis of variance was used to statistically determine the magnitude of bias due to temperature or humidity. In general, humidity and temperature affected readings of both brands of gas detector tubes, and the severity of the bias observed was dependent upon the concentration of the contaminant being measured. The authors state that if the environmental conditions used in these tests had been required in the certification program, eight of the twelve certified tubes would have failed the test.
NIOSH-Author; Chemical-agent-detectors; Environmental-factors; Air-sampling-equipment; Analytical-instruments; Climatic-factors; Hot-environments; Humidity
630-08-0; 124-38-9; 10102-43-9; 10102-44-0; 7446-09-5; 7783-06-4; 50-00-0
American Industrial Hygiene Association Journal