Verification of Passive Monitor Performance: Applications.
Kennedy-ER; Cassinelli-ME; Hull-RD
Diffusive Sampling. An Alternative Approach to Workplace Air Monitoring, Proceedings of an International Symposium, Luxembourg, 22-26 September 1986 1987:203-208
The results of a validation study of passive diffusive dosimeters were summarized. Eleven commercially available passive monitors and one dosimeter using a permeation sampling mechanism designed to detect formaldehyde (50000), sulfur-dioxide (7446095), or ammonia (7664417) were tested. The diffusion monitors included solid sorbent or liquid absorbent based on length of stain direct reading types. They were tested according to a NIOSH protocol that evaluated analytical recovery, sampling rate and capacity, reverse diffusion, storage stability, the effects of analyte concentration, exposure time, face velocity, relative humidity, interferences, monitor orientation, temperature effects, and precision and accuracy. Except for the recovery experiment in which all monitors had acceptable recoveries, at least one performance problem was detected with at least one monitor in each experiment. The most frequently seen problems included variable sampling rates, high sensitivity to humidity and interferents, high bias for short sampling periods, and blank variability and liquid sorbent volume variations. Some of the problems, such as humidity sensitivity, blank variability and liquid sorbent volume variations, were detected only in monitors that had been aged by storing. The authors conclude that the basic concept of passive monitoring is very attractive; however, it has important limitations that are frequently not recognized. The NIOSH protocol is useful for defining the limitations of passive sampler performance.
Air-sampling-equipment; Laboratory-testing; Equipment-reliability; Industrial-hygiene; Air-quality-monitoring; Air-sampling-techniques; Gas-detectors;
50-00-0; 7446-09-5; 7664-41-7;
Berlin-A; Brown-RH; Saunders-KJ;
Diffusive Sampling. An Alternative Approach to Workplace Air Monitoring, Proceedings of an International Symposium, Luxembourg, 22-26 September 1986