Gas sampling devices are used for volume-corrected sampling of gaseous material for imission and emmission, measurements to trace workplace pollutants and to analyse process gases. A microprocessor controls and monitors the sampling process. In automatic mode, gas sampling devices can be used for sampling volumes up to 9,999 litres. Depending on the resistance of the probes, the filter and collector, the sample gas flows at a rate of 12 to 720 l/hr. That meets the requirements of all VDI guidelines and other national and international regulations. The GS 212 gas sampler and the advanced GS 312 can be used in the 0.2 -12 I/min. range. The clear and concise menu simplifies adjustment and minimises errors. Both devices require a power supply of just 12 V DC at a max. of 2A. The devices can also be run independently for 10 hours at a medium pump rate.