Particulate Analyzers are suited for in-use measurements.

Press Release Summary:

SEMTECH QCM (quartz crystal microbalance) and MPS (micro-proportional sampler) provide transient, mass measurement of particulate matter (PM) in engine exhausts. Former calculates mass of PM with resolution approaching 1 nanogram. SEMTECH MPS delivers response times of 0.1 sec and operational speeds of greater than 5 Hz. Based on Labview® platform, both are configurable for short, high-mass deposits or long-term sampling.

Original Press Release:

Semtech QCM, MPS Provide Accurate, Dynamic Particulate Mass Measurement

Saline, Mich., Oct. 29 - Sensors, Inc., introduces the SEMTECH QCM (quartz crystal microbalance) and MPS (micro-proportional sampler) to provide accurate, dynamic, mass measurement of the particulate matter (PM) in engine exhausts. These critical tools will greatly assist in the development of vehicles designed to meet increasingly stringent emissions regulations, including the 2007 HDV PM standards.

Sensors, Inc. recently acquired world-wide manufacturing and distribution rights to QCM and MPS from their designer, Booker Systems, Ltd. of Lytham, Lancashire, England.

"The ability to provide transient, mass measurement of PM is in keeping with our mission to provide robust analytical systems capable of measuring in-use vehicle emissions," says Andrew Reading, president of Sensors, Inc. "It is a tremendous complement to our current SEMTECH range of products, which measure the gaseous emissions from both diesel and gasoline powered vehicles."

Operation of the SEMTECH QCM is quite simple. Electrostatic precipitation - the same technology used in many indoor air purifiers and manufacturing paint facilities - collects aerosol particles from a known volume of air and deposits them on an oscillating piezoelectric crystal. The natural oscillation frequency of the crystal is approximately 5MHz but this frequency is reduced in proportion to the amount of material deposited on its surface. By measuring these shifts in frequency, the SEMTECH QCM can calculate the mass of the particulate matter with a resolution approaching one thousand millionth of a gram, or one nanogram. Operation of the QCM at such a high frequency also makes the system immune to shock and vibration, which is obviously important for in-use measurements.

SEMTECH QCM offers several important features, including:
o Traceability and precise direct mass measurement
o Fast response with high sensitivity
o Configurability for short, high-mass deposits or long-term sampling in workplace or ambient outdoor environments
o Small size and lightweight for portable applications

To complement the QCM, the MPS was developed to permit transient, in-use measurements. Typically, Constant Volume Sampling Systems (CVS) and their derivatives are highly accurate in steady-state operation, but accuracy may suffer in transient modes due to the delay in getting the sample from the exhaust to the sample point, as well as the delay in flow control of the dilution tunnel. The CVS system is also impractical for in-use applications.

The SEMTECH MPS, however, delivers response times of 0.1s and operational speeds of greater than 5 Hz. In addition, the unit is small enough to be easily transportable, and, as a 12 VDC system, is quite practical for field use.

Software for the SEMTECH QCM and MPS is based on a Labview® platform. This powerful, flexible software allows the SEMTECH QCM and MPS to be configured to specific measurement requirements. Because the sophisticated design of the SEMTECH QCM and MPS can accept input from other measurement devices through its CAN bus interface, all data can be collected in a single file for later analysis.

"The SEMTECH QCM and MPS are the right products at the right time, as increasingly stringent PM standards are promulgated," says Robert Wilson, vice president of marketing and sales for Sensors, Inc.

"Tougher standards and penalties for non-attainment areas will compel vehicle manufacturers to better control particulate emissions. SEMTECH QCM and MPS are ideal tools for the development of cleaner vehicles and their emissions control systems."

Sensors, Inc. is the leading provider of in-use emission measurement systems for a variety of applications, world-wide.


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