P5.4 - Low-cost chemical gas sensors for selective formaldehyde quantification at ppb-level in the field

Event
AMA Conferences 2017
2017-05-30 - 2017-06-01
Nürnberg, Germany
Band
Proceedings Sensor 2017
Chapter
P5 - Gas, Chemo and Biosensors
Author(s)
M. Bastuck, A. Schütze - Saarland University, Saarbrücken (Germany), D. Puglisi, P. Möller, A. Lloyd Spetz, M. Andersson - Linköping University (Sweden), W. Reimringer - 3S GmbH, Saarbrücken (Germany)
Pages
702 - 707
DOI
10.5162/sensor2017/P5.4
ISBN
978-3-9816876-4-4
Price
free

Abstract

Data from a silicon carbide based field-effect transistor were recorded over a period of nine days in a ventilated school room. For enhanced sensitivity and selectivity especially to formaldehyde, porous iridium on pulsed laser deposited tungsten trioxide was used as sensitive layer, in combination with temperature cycled operation and subsequent multivariate data processing techniques. The sensor signal was compared to reference measurements for formaldehyde concentration, CO2 concentration, temperature, and relative humidity. The results show a distinct pattern for the reference formaldehyde concentration, arising from the day/night cycle. Taking this into account, the projections of both principal component analysis and partial least squares regression lead to almost the same result concerning correlation to the reference. The sensor shows cross-sensitivity to an unidentified component of human activity, presumably breath, and, possibly, to other compounds appearing together with formaldehyde in indoor air. Nevertheless, the sensor is able to detect and partially quantify formaldehyde below 40 ppb with a correlation to the reference of 0.48 and negligible interference from ambient temperature or relative humidity.

Download