Davenport, JohnHodgkinson, JaneSaffell, John R.Tatam, Ralph P.Berghmans, F.Mignani, A. G.De Moor, P.2014-09-022014-09-022014-05-22J. J. Davenport, J. Hodgkinson, J. R. Saffell, R. P. Tatam, Formaldehyde sensor using non-dispersive UV spectroscopy at 340nm, Proceedings of Optical Sensing and Detection III, volume 9141, held in 14th April, Brussels, Belgium, Proceedings of SPIE 9141, 91410K (May 15, 2014).97816284108910277-786Xhttp://dx.doi.org/10.1117/12.2052460http://dspace.lib.cranfield.ac.uk/handle/1826/8668Formaldehyde is a volatile organic compound that exists as a gas at room temperature. It is hazardous to human health causing irritation of the eyes, nose and throat, headaches, limited pulmonary function and is a potential human carcinogen. Sources include incomplete combustion, numerous modern building materials and vehicle fumes. Here we describe a simple method for detecting formaldehyde using low resolution non-dispersive UV absorption spectroscopy for the first time. A two channel system has been developed, making use of a strong absorption peak at 339nm and a neighbouring region of negligible absorption at 336nm as a reference. Using a modulated UV LED as a light source and narrowband filters to select the desired spectral bands, a simple detection system was constructed that was specifically targeted at formaldehyde. A minimum detectable absorbance of 4.5 × 10-5 AU was estimated (as ΔI/I0), corresponding to a limit of detection of approximately 6.6 ppm for a 195mm gas cell, with a response time of 20s. However, thermally-induced drift in the LED spectral output caused this to deteriorate over longer time periods to around 30 ppm or 2 × 10-4 AUCopyright 2014 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.Conference paper