Portable device for the in-line measurement of the hydrogen sulfide concentration of an off-gas

A kit for measuring a hydrogen sulfide concentration of a gas likely to contain hydrogen sulfide, wherein the kit comprises separate modules that can be connected to one another, the modules comprising:

• a measurement module A comprising a measurement chamber M wherein an absorption of a monochromatic electromagnetic radiation by the gas likely to contain hydrogen sulfide is measured and an absorption measurement related to the hydrogen sulfide concentration is produced, and wherein the measurement module A has a range of working pressure values;
• an expansion module B that brings the pressure of the gas likely to contain hydrogen sulfide to the range of working pressure values of the measurement module A;
• a pressure-regulating module C that maintains the pressure of the gas likely to contain hydrogen sulfide in the measurement chamber M at a pressure lying within the range of working pressure values of the measurement module A;
• a processing module D that processes the absorption measurement, whereby the concentration of hydrogen sulfide in the gas likely to contain hydrogen sulfide is determined.