High-speed, accurate gas recognition and concentration estimates by the time-division method

Abstract

There are increasing demands for gas sensors in various fields such as food, cosmetics, and safety applications, and a method is required which can recognize the existence of a gas quickly and with high accuracy, as well as a method to measure the gas concentration quantitatively. In the system proposed in this paper, the gas is recognized and its concentration is estimated by using a quartz crystal resonator sensor. The sensor can detect various gases, but may require a long time, depending on the type of gas, due to its operating principle. In the proposed method, the response of the sensor is monitored in time division, considering the time from the start of the response to detection, so that the gas is detected in a short time. In addition, a procedure is included in which the certainty of the results of recognition is examined, so that the gas type can be determined with stability. The effectiveness of the proposed system is shown by applying the method to common organic solvent gases. © 2000 Scripta Technica, Syst Comp Jpn, 31(6); 45–55, 2000