Low-temperature catalytic conversion plus UV-DOAS for continuous total mercury measurement.
System 400Hg measures total gaseous mercury in flue gas. A heated probe extracts the sample, a catalytic converter converts oxidised mercury to elemental mercury, and the DOAS analyser measures the elemental mercury absorption to report THg.
The mercury module can be added to an existing OPSIS System 400 CEMS sharing the same AR600 analyser, so mercury and the regular CEMS parameters are measured by one system.
| Measurement principle | Low-temperature catalytic conversion + UV-DOAS |
| Conversion temperature | 200 °C |
| Conversion efficiency | > 99 % (Hg²⁺ → Hg⁰) |
| Detection limit | 0.5 µg/m³ (1 m path, 5 s) |
| Measuring range | 0–1000 µg/m³ (Hg⁰ / THg) |
| EN 15267 certified range | 0–10 µg/m³ |
| Certification | TÜV QAL1 · MCERTS · CCEP |
Typical data from OPSIS product documentation; specifications depend on the application and are confirmed at quotation stage.
What is the conversion principle?
Oxidised mercury compounds such as HgCl₂ are converted to elemental mercury in a catalytic converter at about 200 °C, with efficiency above 99 %. The DOAS analyser then measures elemental mercury at 253.7 nm.
What is the detection limit?
0.5 µg/m³ at a 1 m path and 5 s measurement time; the EN 15267 certified range is 0–10 µg/m³.
Send the gases, ranges, duct or path dimensions and required certification — we will respond with a technical proposal.