ABSTRACT
This chapter describes the nature and types of toxic gases and focuses on the continuous automatic toxic gas monitors and their sampling systems. It discusses the discontinuous monitoring devices, such as the personnel protection and dosage sensors which measure the combined effect of toxic gas concentration and duration of exposure. Toxic gases or vapors affect the human body through the bronchopulmonary system by absorption through the skin, and/or through ingestion. Optical methods are gaining increased usage in toxic gas monitoring, at the expense mainly of gas chromatography, which is in a slow decline. A grab sampling device used for toxic gas monitoring in atmospheric air can be a sampling bag or a rigid container. In the sensor used in toxic gas monitoring, the toxic gas molecules penetrate the membrane and react with the electrolyte causing a current or potential change between the electrodes. Toxic gas and vapor monitors are only as good as their calibration.
