A designed flow-through microsystem for accurate and fast measurement of gas sensors at the ppb level

Abstract

Abstract The characteristic parameters of gas sensors depend highly on the method used to evaluate them. This paper presents a flow-through microsystem for accurate and fast measurement of gas sensors, especially for the sensor with a fast response and high sensitivity at the ppb level. The microsystem consists of four parts, i.e. a dynamic multiple gas handling unit, a test gas preheater, an olive-like test chamber with an inner volume of 4.98 ml and data analysis apparatus. Thereinto, the multiple gas handling unit was constructed to meet the needs of dynamical sensor response tests, and the olive-like test chamber was designed based on the principles of low background interference and fast replacement of ambient conditions, which was optimized by computational fluid dynamics simulation and verified by its airtightness and applicable flow rate range. For a flow rate of 300 ml min−1, it can discern that the replacement time for the chamber ambient gas test was about 1 s. Finally, performance tests for two commercial sensors and one home-made sensor were carried out on this microsystem. The results showed that this system can serve as a means of highly sensitive (ppb level) and fast gas sensor evaluation, and the measured values obtained by this system can be considered to be closer to a sensor’s true values.