There is an urgent need for reliable and stable sensing systems for the quality of air in various environments. The commercial market is rapidly growing for efficient and trustable climate control sensors. This implies the development of gas sensors with greater reliability and reproducibility with improved sensitivity, selectivity and stability. The objective of this project was to design an improved cabin air quality sensing system for the automotive market, which is superior to the present commercial products. Spin-off products are also envisaged.
Portable cabin air analyzers (demonstrator units) have been designed, manufactured and tested. These units consist of electronic printed circuit board modules containing: 2 silicon micro-machined array devices with up to 6 metal oxide resistive gas sensors, up to 6 conducting polymer resistive gas sensors, an array of 4 polymer-coated quartz crystal microbalances, and an array of 5 catalytic coated MOSFET gas sensors. The demonstrator units contain the modules together with a Peltier cooler, 3 electric fans, 2 temperature sensors and a humidity sensor. The units are operated via a notebook PC, in which National Instruments DAQ 700 & DAQ 1200 data acquisition cards were fitted. Virtual instrumentation's (VI) were written using the commercial software (LabVIEW) to control the operation, log data and display the results.
The units have been sent to VDO (Germany) and Fiat (Italy) for evaluation. Extensive test runs have been carried out in order to measure the pollution levels on inner city and urban routes. The results of these experiments show that the outside pollution levels can be measured and analyzed using the demonstrator unit.