Whether in industrial settings, manufacturing facilities, or as a matter of lab safety, gas monitors help protect workers by assessing their exposure to toxic and combustible gases. Air monitoring equipment is available in different varieties: an assessment must be conducted of potential hazards and then appropriate equipment chosen for use.
Here’s a description of various types of gas monitors:
Gas Detection Badges—there are two types: badges with a color change indicating the presence of the gas in question; and badges that are sent to a lab after use for analysis. Badges with color change indicators are designed for a single chemical, but have the advantage of showing immediate results. The badges sent in for analysis can be used to sample a broader array of chemicals with higher accuracy at lower levels of concentration.
Gas Detection Tubes—there are two types: diffusion tubes and detector tubes that use a pump. Diffusion tubes allow gas to enter the tube through diffusion, react with the reagent, and produce a color change with exposure levels read from markings on the tube. These are used for time-weight average (TWA) calculations. Detector tubes are used with a hand pump for quick sampling of an area vs. longer term measurements for an individual worker.
Single- and Multi-Gas Detectors—Can be worn by a worker or handheld, giving an immediate reading of gas concentration. Visible and/or audible alarms alert you to high toxic gas concentrations, or low oxygen levels. Some models have data logging capabilities for later download to a computer for record-keeping purposes.
Photo-ionization detectors (PID) detect volatile organic compounds (VOCs). They are sensitive to a broad band of VOCs eliminating the need for multiple sensors. For best results, they should be calibrated using the target gas.