MEASUREMENT OF CO AND NO2 GAS CONCENTRATION'S BY MULTISENSOR MICROSYSTEM IN THE MODE OF PULSE HEATING

Abstract

The most promising for mass use in gas analysis equipment are semiconductor gas sensors due to their high reliability, easy operation and relatively low cost. Power consumption in the single-sensor mode, constant heating is from 250 to 600 W average and in pulsed mode heating – ≤ 20 W. The aim of this work was to study the effectiveness of the pulsed heating for multisensor microsystems consisting of two sensors on the substrate of the nanostructured aluminum oxide, compared with the mode of constant heating.For sensitive layers were chosen compositions: SnO2+Pt+Pd at the first sensor of the microsystem and In2O3+Al2O3+Pt on the second. Measuring the sensor response in the pulse heating mode was carried out as follows. Power on each sensor microsystem was installed 1.3 mW. Then the short-term heating (theat.. = 5 s) was performed at the power 61 mW. The detected gases CO and NO2 with the concentration 200 ppm and 4 ppm, correspondingly, were submitted to the microsystem after 15 minutes. The resistance values for each of the sensor were fixed. According to the results determine the sensitivity (sensor response) the maximum value is after 60 s for the sensor with a sensing layer SnO2+Pt+Pd when exposed to CO was 670 %, and for the sensor with In2O3+Al2O3+Pt – 380 %.Advantages of using pulsed heating from the point of view of a power consumption multisensor microsystem mW-range and high performance sensors on substrates of nanostructured alumina were established.

Keywords

• multisensory gas microsystem
• mode pulse heating
• the concentration of gases co and no2