24 March 2006
Finland’s Dekati Oy has developed a new sensor-based instrument to measure particulate emissions from vehicles. The AutoTest instrument, to be launched this year, is intended for real time measurement of tailpipe PM levels in vehicle inspection and maintenance (I&M) programs and other raw exhaust applications.
The instrument utilizes Dekati’s Electrical Tailpipe PM Sensor (ETaPS). The ETaPS is an in-situ flow-through PM sensor for diesel and gasoline engine PM measurement and monitoring applications. The sensor is capable of both steady-state and transient measurement. ETaPS in-situ measurement technology eliminates the need for PM sampling and dilution equipment, making it suitable for in-use testing.
ETaPS is based on the principle of particle charging and electrical detection. When exhaust flow passes through a corona discharge charging chamber, a known amount of charge is attached to all solid and volatile particles. The charge carried by particles leaving the charging cage is then measured with a sensitive electrometer. This signal is proportional to the amount of particles emitted by the engine. This technology provides rapid response and wide dynamic range, from diesel particulate filter equipped vehicles up to high emission levels of old heavy-duty diesel engines, said Dekati.
Traditionally, smoke opacity meters have been used in vehicle I&M programs. Opacity meters, however, have limited sensitivity and are not suitable for PM measurements from new diesel engines, especially those fitted with particulate filters. Dekati estimates the worldwide market potential for the AutoTest instrument to be between 80,000 and 200,000 units by 2012.
Other applications of the sensor include industrial hygiene, where the arrival of nanomaterials in the everyday working environment constitutes a potential health risk for persons handling the materials. It is also possible to use the same technology to develop on-board PM sensors for future diesel OBD systems, said Dekati.
The instrument has been developed in cooperation with Environmental Systems Products (ESP) of Tucson, AZ, and Tampere University of Technology in Finland, and partly funded by Tekes, the Finnish Funding Agency for Technology and Innovation.