The American Conference of Governmental Industrial Hygienists (ACGIH) has developed Threshold Limit Values (TLVs) for vibration exposure to hand-held tools. This instrument is used extensively in Department of Defense depots where chemical agents are stored and used by other agencies in the field. This technique can only be used for assessing contaminants that would not react over time inside the bag.
Some equipment must be field calibrated or serviced prior to use. Various styles and materials for wipes and sponges are available. As with swabs, synthetic materials are recommended to eliminate potential interference problems with detection systems. Interference from other gases can be a problem. Lifeloc’s top of the line professional breath alcohol testing devices, the FC20 and the FC20BT, are the most advanced and feature rich on the market.
The electret charge is measured before and after the exposure with a portable electret voltage reader, and the rate of change of the charge (change divided by the time of exposure) is proportional to the concentration of radon in the area. Before using field instrumentation, check the calibration sticker and ensure that the instrument is within its calibration due date. The measurement device is generally an accelerometer mounted in a hard rubber disc. Warm-up time — how long does the unit need to be powered on before it can produce accurate readings? Excessive buildup of particles in the sensing chamber may affect the accuracy of measurements. The C8 paper is equivalent to the M8 paper; the «C» indicates a version manufactured for commercial use.