Direct-reading Dräger diffusion tubes are used to determine average concentrations or time-weighted averages over a period of 1-8 hours. The direct-reading Dräger-Tubes are attached to the clothing with a mount at breathing height as passive measuring system, thus without using a Dräger tube pump. According to the principle of diffusion the harmful molecules enter the diffusion tube. The offered Dräger-Tube has the following standard measuring ranges: 10-200 ppm/1 h 1.3-25 ppm/8 h Measurements: 10