A 4-PROBE TYPE GAS SENSOR USING A SOLID-STATE PROTON CONDUCTOR SENSITIVE TO HYDROGEN AT ROOM-TEMPERATURE

The authors describe the newly designed four-probe type sensor which is as sensitive to H//2 as the amperometric sensor at room temperature but is insensitive to humidity. Although DELTA E//A //g was zero in the air flow, its value increased rapidly when the sample gas was passed over the sensing electrode. The 90% response time was about 20 s and the stationary potential value was about 20 mV. When the air flow was resumed, DELTA E//A//g returned to zero within about 40 s. Based on experimental data it is concluded that the four-probe type sensor devised is not only sensitive to H//2 in air at room temperature, but also can operate without calibration for the ambient humidity.