Method and device for measuring low toxic vapour concentrations, in particular concentrations of mercury vapour

• Main Author: BARDEY, WOLFGANG, 45131 ESSEN, DE
• Format: Patent
• Language: English; German
• Published: 19.01.1995
• Edition: 6
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

The invention relates to a method for measuring low toxic vapour concentrations, in particular mercury vapour concentrations, with the aid of a pollutant-collection medium, in which the pollutant-collection medium absorbs the pollutant from a known gas quantity containing the toxic vapour, in which entry of further gas loaded with pollutant into the measuring apparatus is then blocked, in which, by heating the pollutant-collection medium, the pollutant absorbed therein is then again released into the gas volume, of known size, which is now closed off, and in which the toxic vapour concentration present in the closed-off gas volume is then measured. It is characterised in that, shortly after essentially complete release of the pollutant from the pollutant-collection medium, the toxic vapour is removed by a partial gas volume from the pollutant-collection medium and the toxic-vapour concentration is subsequently measured only in this separated, i.e. no longer containing the pollutant-collection medium, partial gas volume. A further subject of the invention is a method, in which a particular base toxic-vapour concentration is set in the measuring apparatus by introducing a gas quantity containing a toxic vapour (doping) and, during the measurement, the toxic vapour concentration is calculated by subtracting the base toxic vapour concentration from the measured value.