Demonstration of a Gas-Sensing Application for a Gas Switch Device Using the LabVIEW-Based Measurement System

Abstract

A standard ceramic method was used to prepare ZnO+0.01Sb₂O₃ ceramics. The measurements and processing of the data were made using: an LP connector, a data acquisition card, a computer and the LabVIEW program. The gas-response characteristics of the sample to NH₃ vapor were investigated. Result showed that the resistance of the sample at room temperature decreased in the interval of 4.4 MΩ –3.7 MW in the presence of NH₃ gas at 30°C in normal atmospheric conditions. NH₃ gas responsivity (G) was -15.909%. The result indicated a potential application in a low-cost NH₃ gas switch device. The application of ZnO+0.01Sb₂O₃ gas ceramics as an NH3 gas switch device was investigated at room temperature. The results showed that the voltage drop across the sample decreased in the presence of NH₃ gas. The operation as an NH3 gas switch device used the comparison of the voltage drop across the sample with a setpoint voltage (2.03 V). This result controlled the operation of a relay, solid state relay
and gas alarm, respectively. It showed that the sample could be used as an NH₃ gas switch. The system has been in operation for a year and all components have functioned well.