CO GAS-SENSING PROPERTIES OF ZNO/CUO CONTACT CERAMICS

Abstract

The CO gas-sensing properties of ZnO/CuO contact ceramics have been investigated at 100-320-degrees-C. The interfacial resistance change with CO concentration has been verified by complex-impedance measurements. The sensing properties are largely determined by ZnO, judging from the I-V characteristics and the temperature and voltage dependences of the sensitivities. The sensitivity, almost-equal-to 13 in 1% CO at 260-degrees-C, is found to be proportional to the square root of the CO partial pressure. Although the maximum sensitivity is nearly the same for H-2 gas, the temperature dependence of the sensitivity is different from that for CO.