P3.5 - Non-contact Measuring the Surface Temperature of Chemical Sensors
- Event
- SENSOR+TEST Conferences 2009
2009-05-26 - 2009-05-28
Congress Center Nürnberg - Band
- Proceedings SENSOR 2009, Volume II
- Chapter
- P3 - Chemo-/Bio-Sensors
- Author(s)
- K. Kadlec - Institute of Chemical Technology, Prague, Czech Republic
- Pages
- 335 - 340
- DOI
- 10.5162/sensor09/v2/p3.5
- ISBN
- 978-3-9810993-5-5
- Price
- free
Abstract
Pellistor and semiconductor sensors are used for measuring the concentrations of combustible or toxic gases and organic volatile vapours. The functional properties of these chemical sensors depend on their working temperature to a large extent. The working temperatures of sensors are usually within the temperature range of 200 – 600 °C. The knowledge of both the sensor active layer temperature and the temperature dependence of the sensor output signal is very important for the optimum setting of sensor working parameters.
Up to now the surface temperature of sensor active layer has been usually determined by measuring the electrical resistance of the heating element, which consists in either a platinum wire in bead sensors, or a platinum heating meander in flat sensors. For measuring the sensor surface temperatures the application of contact-less measurement using an IR thermometer presents itself. A wide variety of instruments is available on the market, which are able to measure temperatures within the range of concern. The problem consists, however, in the size of the sensed area of the object of measurement. The majority of commercially available contact-less thermometers can sense temperatures of target surfaces larger than 3 - 5 mm in diameter. However, the measurement of chemical sensor surface temperatures calls for the target or measuring field to be of about 1 mm or less in diameter.