Accurate H2S measurements in high H2 concentrations

MEMBRAPOR‘s special 4-electrode sensor is used for target gases such as hydrogen sulphide (H2S). It compensates for interfering hydrogen (H2) gas, which is not possible to eliminate when using filters or other techniques. In applications, where the H2 concentration is very high, or where the concentration of the target gas is very low, the sensor signal has to be corrected to respond to H2. While both, the oxidation of H2S and interfering H2 occur at the sensing electrode, the signal at the auxiliary electrode is almost exclusively caused by H2. With two signals caused by two gases, the respective concentrations can easily be calculated and thus, a highly accurate H2S reading is obtained in applications where normal 3-electrode sensors would fail.