[A device for studying the dynamic response of a gas analyser (author's transl)]

A mechanical device has been built, enabling one to produce a step change in gas concentration at the inlet of gas analyser. It is made of two chambers filled each with a different gas mixture and sliding rapidly in a cylinder in such a way that the probe from the gas analyser is exposed sequentially to the two gas mixtures. The total translation time is 6 ms. The devise has been used to study the response of a quadrupole mass spectrometer. Both the delay and the response time vary with the gas mixtures and/or the direction of the concentration changes.