Sensors in the Measurement of Toxic Gases in the Air

摘要: The use of sensors to measure toxic gases and vapors in air has increased rapidly due several factors, including a growing public awareness the hazards associated with many airborne chemicals, increasing regulatory requirements for industries using hazardous continuous advancements technology instrumentation available these compounds. principal advantage sensor systems relative traditional sampling analytical methods, is ability chemicals over short time periods, that is, matter seconds or minutes, thus providing information necessary protect workers from acute health effects. Modern sensor-based provides options processing storing measurements, thereby allowing extreme flexibility evaluating exposures ceiling limits, short-term exposure limits (STELs), longer term average concentrations based on user selectable periods. This range data makes an attractive, some cases, only alternative measuring air. Most devices can be broadly categorized as: (1) electrochemical which constitute vast majority currently detection vapors; (2) mass are piezoelectric materials surface acoustic wave (SAW) devices; (3) optical rely interaction electromagnetic radiation analyte, resulting alteration properties radiation. most common applications include industrial hygiene monitoring, confined space process emission leak detection.