Air sampling instruments for evaluation of atmospheric contaminants, 9th edition. Cohen BS, McCammon CS Jr., eds. Cincinnati, OH: American Conference of Governmental Industrial Hygienists (ACGIH), 2001 May; :507-576
This chapter presents useful information about direct-reading instruments for analyzing airborne gases and vapors. The instrumentation that will be discussed is that which provides an on-site indication, in useful units (e.g., ppm, mg/m3, etc.), of the presence of the contaminant(s) of interest. Frequently, these instruments are general, nonspecific detectors, but chemispecific detectors are also available. The instruments are commercially available. Direct-reading instruments may be used for area, process, or personal monitoring, and it is convenient to describe three physical classifications for grouping these instruments: personal instruments are those instruments small enough to be worn by an individual; portable instruments are those easily carried by an individual; transportable instruments are those requiring a cart or other support for movement to or from the monitoring site. Ideally, these instruments operate from self-contained battery power, but many can also use, and some require, line current. In this chapter, the reader will find information on operational, physical, and performance characteristics for each of the instruments described. These instruments are grouped into the following classifications: electrochemical instruments, spectrochemical instruments, thermochemical instruments, gas chromatographic instruments, mass spectrometers, paramagnetic instruments, and an aerosol formation and detection instrument. In each section, there is a general definition of the instrumentation to be described, an explanation of the principle of detection, and a brief discussion of conditions of application for the instruments, including capabilities, restrictions, and limitations. At the end of the chapter is a suggested reading list for the reader who requires more in-depth information about a particular technique. Regardless of the instrument chosen for use and the capabilities of that instrument, there is no substitute for knowledge of the capabilities and limitations of the instrument as well as effects of the conditions in the proposed monitoring situation. Then, the most appropriate instrument can be chosen for a given application, meaningful data can be obtained, and, if necessary, effective solutions for contaminant control can be implemented.