Research Project Information

Research Project Summary Information

Development of Continuous Amb. Particulate Monitor(ST5060-1)

Rupprecht & Patashnick, Co


The National Ambient Air Quality Standard (NAAQS), revised by the U.S. Environmental Protection Agency (EPA) in July 1997, added new annual and 24-hour standards for particulate matter less than 2.5 microns (PM2.5) in aerodynamic diameter in ambient air. Although a recent U.S. Court recently overturned these standards, the EPA and states are establishing a monitoring network to measure PM2.5. The PM2.5 Federal Reference Method (FRM) sampler is a manual single or sequential filter-based sampler that collects a 24-hour sample, which has to be brought to a laboratory for weighing under standard conditions. Rupprecht & Patashnick, Inc. (R&P) have pioneered continuous measurement of ambient fine particle mass using Tapered Element Oscillating Microbalance (TEOM) technology, which if adapted to collect samples consistent with the FRM would reduce the cost of data collection and improve the level of information on PM2.5 in air.

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Project Description

The Contractor developed an add-on device to reduce the humidity of sample: air for TEOM Series 1400a Ambient Particulate Monitor for PM10 and PM2.5, which operates near ambient during warm/humid summer months when moisture influences mass measurements. The dryer, called the sample equilibration system, was tested in the laboratory and in the field by the Atmospheric Science Research Center (ASRC). Performance of the prototype SES ambient PM2.5 monitor and FRM filter-based samplers were compared and assessed.


The project validated consistency with FRM measurements in addition to real-time data. Although the SES TEOM is not accepted as an alternative method, the automated, real-time feature reduces the cost of ambient monitoring by drastically reducing filter replacement.

Project Results

There is a high degree of correlation between the SES TEOM and the FRM and provides continuous data on PM2.5. The SES operating at 30 degree C captures 5-10% more mass than when the TEOM is operated at 50 degree C. R&P introduced the SES for sale in the spring of 2000. More than 150 units have been sold.


Rupprecht & Patashnick, Co
26 Tech Valley Drive
East Greenbush, NY 12061

Principle Investigator

Jeff Ambs

Universities Involved


Project Type:

Research Study

Technologies Types:

NYSERDA Contact Information

Barry Liebowitz


R&D -Transport & Power Systems

Contract Details

Start Date: 1/11/2010
Project Status: Active
Contract Number: ST5060-1

Last Updated: 6/28/2013