MEMBRAPOR‘s special 4-electrode sensor is used for target gases like hydrogen sulfide (H2S) and allows to compensate for interfering hydrogen (H2) gas, which is not possible to eliminate with 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 for the response 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 due to 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 3-electrode sensors would fail.