Gas Analyzer for Measuring the Mercury Content of a Gas
The invention relates to a gas analyzer for measuring the mercury content of a gas having an Hg light source which transmits transmitted light having wavelengths of at least one spectral line of the mercury, a measuring cell in which the gas to be measured is present, a light receiver, an evaluation unit and a test cuvette which can be introduced into the beam path for checking the operability. To provide an improved gas analyzer which can be calibrated in a simple manner as well as a corresponding improved calibration method, provision is made that the test cuvette contains benzol as a test gas.
1 . A mercury gas analyzer for measuring the mercury content of a gas having an Hg light source which transmits transmitted light having wavelengths of at least one spectral line of the mercury, a measuring cell including gas containing mercury, a light receiver, an evaluation unit and a test cuvette which can be introduced into the beam path for checking the operability, wherein the test cuvette contains benzol as a test gas.
2 . A gas analyzer in accordance with claim 1 , wherein the concentration of the benzol amounts to 1%.
3 . A gas analyzer in accordance with claim 1 , wherein the optical light path length in the test cuvette amounts to approximately 2 cm.
4 . A gas analyzer in accordance with claim 1 , wherein the pressure in the test cuvette amounts to approximately 1000 mbar.
5 . A gas analyzer in accordance with claim 1 , wherein the temperature in the test cuvette lies approximately between room temperature and 50° C.
6 . A gas analyzer in accordance with claim 1 , wherein a plurality of mutually connected test cuvettes each having different optical path lengths is provided.
7 . A method of calibrating a mercury gas analyzer, comprising the steps:
generating light having wavelengths of at least one Hg spectral line by an Hg light source;
providing a test cuvette with benzol of a known concentration as a test gas and thus with known calibration values of the test cuvette at the wavelengths of the Hg spectral line;
inserting the test cuvette into the beam path; and
calibrating the gas analyzer to the known calibration values.
8 . A method in accordance with claim 7 , wherein, on the putting into operation of the gas analyzer, the gas analyzer is first calibrated for the first time by means of charging a known mercury concentration into the measuring cuvette and then a measured value for the test cuvette is determined and is saved as a calibration value and the currently obtained measured value is compared with the calibration value in all following calibrations with the test cuvette and the gas analyzer is thus calibrated in operation.
9 . A method in accordance with claim 7 , wherein different test cuvettes having different optical wavelengths are used.