Sensors & Transducers e-Digest, Vol. 48, Issue 10, October 2004: Technology News
(ISSN 1726- 5479)
Microsystem Technology Breaks Mew Ground
in Dew Point and Fluidic Metering
Villingen-Schwenningen / Munich - Microsystem technology breaks new ground in dew point and flow sensor technology. At Electronica 2004 (Munich, 9-12 November 2004) the Institute for Micromachining and Information Technology of the Hahn-Schickard Gesellschaft (HSG-IMIT), a R & D service provider in microsystem technology, will introduce a new type of sensor operating on thermal principles metering humidity or volume fluidics with a heated silicon membrane.
With the development of a thermal dew point sensor, the Institute rings in a new chapter in humidity metering. Manufacturing costs lie approximately 90 per cent below those of comparable precision dew point sensors. The microsensor with long-term stability fits into a match head and in borderline cases also meters more exactly than many standard sensors operating on optical or capacitive principles. The access period is currently less than 10 seconds. HSG-IMIT believes a reaction time of milliseconds possible. In addition the thermal dew point sensor can test and calibrate itself. Limitations as known from other sensors such as hysteresis or incorrect metering values due to conductive condensation do not occur here at all.
HSG-IMIT's thermal flow meter can monitor mass flow of fluidic media in channels with cross-sections from 600x300 micrometer. Its metering ranges lie between 0,1 ml/min and 10 l/min for gases or between 10 µl/h and 10 l/h for fluids. The sensor even recognizes if a fluid moves only one tenth of a millimetre and reacts in milliseconds.
As in thermal dew point sensors the head of the flow sensor consists of a silicon nitrite membrane containing heating element and temperature sensors. If fluids or gases flow over this membrane or if water molecules collect at the dew point on the membrane, heat distribution on the membrane surface alters. The developers at HSG-IMIT utilized this effect in order to determine size and speed of volume flows or dew point temperatures and humidity.
HSG-IMIT sees the main areas of application in industry and in plant engineering and building technology as also in vehicle and medical technology, process control and in biotechnology. To bring the sensor to mass-production maturity, the Institute is searching for partners for additional development of applications.
Dipl.-Ing. Matthias Ashauer,
Institute for Micromachining and Information Technology
of the Hahn-Schickard-Gesellschaft (HSG-IMIT)
Wilhelm-Schickard-Str. 10, 78052 Villingen-Schwenningen, Germany
Tel.: +49 7721 / 943-229
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