GASTEC Color Dosimeter Tubes provide reliable, on-the-spot Time-Weighted Average (TWA) monitoring of worker exposure to gases and vapors. Simple-to-use and easy-to-read, snap off the pre-scored end of the tube and insert it into a tube holder. Place the tube on a worker near the breathing zone, except when measuring carbon dioxide (see second Tech Tip below). No pump, chart, or analysis is needed. Read the printed calibrated scale on the tube for exposure measurement in parts-per-million-hours (ppm-hours). Divide the reading by hours sampled for ppm levels.
- Use dosimeter tubes for measuring workplace exposures from 1 to10 hours. To determine TWA exposure levels, simply divide the color stain indication by the number of hours in the sampling period.
- To avoid overstating carbon dioxide levels because of exhalation, place passive color tubes for carbon dioxide at the waist instead of the normal position in the breathing zone.