Detection of low concentrations of acetone using a gas sensor equipped with A zeolite based pre-concentrator

The detection of acetone using a gas sensor at low concentrations is very important due to its application in the diagnosis of diabetes from breathing, whereas common gas sensors usually do not have such capability. Measurement of acetone in human exhalation is a valid method for diagnosing diabetes, but due to the small amount of acetone in breathing (less than 10 ppm), measuring it using commercial gas sensors has many challenges. In this study, acetone absorption was demonstrated by zeolite A and then the performance of the TGS2602 gas sensor was improved by using zeolite A in acetone gas detection. First, the sensor response was investigated in acetone concentration levels less than 10 ppm. The acetone-contaminated air was then passed through a zeolite substrate to absorb the acetone in the zeolite surface. Immediately after the adsorption stage, the zeolite was heated to 450 ◦C to release the absorbed acetone at once and to create a higher instantaneous concentration in the sensor chamber compared with the initial gas concentration. Due to the increase in concentration at the time of release, the sensor response was improved. With this method, the concentration of the acetone in the sensor chamber increased more than 50 times compared to the incoming acetone polluted air, which increased the sensor response by 7 times. To evaluate the efficiency of the built-in system, the effect of factors such as the mass of the zeolite used, the air flow rate, the adsorption/desorption temperature and the adsorption time were investigated. It has been observed that the sensor equipped with zeolite pre-concentrator, as an easy way, low-cost, and reliable method, increases the detection capability of the commercial sensor beyond the detection threshold.