Grantee Research Project Results
Final Report: Innovative Sampler as a Reference Standard for Measurement of Particulate Matter Mass in Ambient Air
EPA Contract Number: 68D02036Title: Innovative Sampler as a Reference Standard for Measurement of Particulate Matter Mass in Ambient Air
Investigators: Ambs, Jeffrey
Small Business: Rupprecht & Patashnick Co, Inc.
EPA Contact: Richards, April
Phase: I
Project Period: April 1, 2002 through September 30, 2002
Project Amount: $69,914
RFA: Small Business Innovation Research (SBIR) - Phase I (2002) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , SBIR - Monitoring , Small Business Innovation Research (SBIR)
Description:
The Differential Tapered Element Oscillating Microbalance® (TEOM®) monitor has been developed as a continuous monitor reference standard for sampling ambient particulate matter (PM) mass. The new monitor eliminates the problems associated with other particle measurement techniques (including manual filter systems), especially in its handling of volatile material, as a result of the strongest feature of TEOM® instrumentation: direct mass measurement in real time. In addition, the Differential TEOM® monitor was designed to provide this real-time determination of the ambient PM mass at the temperature as it exists in the atmosphere at the time of collection. The goal of this work was to construct prototype Differential TEOM® monitors for field testing under uncontrolled ambient temperature operation of the monitor. The prototype monitors needed to be designed for sampling PM10 aerosol as well as PM2.5 aerosol.The Series 1400a TEOM® monitor, upon which the prototype Differential TEOM® monitors are based, was designed to operate at a fixed control temperature, typically 30°C or 50°C. To satisfy the requirement that the Differential TEOM® monitor sample the ambient PM mass at the conditions as it exists in the atmosphere, the prototype units must operate without the temperature control used in the commercial instruments. As the temperature of the sensing tapered element used in the TEOM® monitor changes, the basic frequency of the element also changes, resulting in an apparent mass change that is tied to the temperature and not a real mass change on the collection filter of the monitor. The Differential TEOM® monitor utilizes a self-referencing method of determining the resultant collection mass. This differential method is capable of resolving these temperature changes in real time and provides a highly accurate measurement of the conceThe Differential Tapered Element Oscillating Microbalance® (TEOM®) monitor has been developed as a continuous monitor reference standard for sampling ambient particulate matter (PM) mass. The new monitor eliminates the problems associated with other particle measurement techniques (including manual filter systems), especially in its handling of volatile material, as a result of the strongest feature of TEOM® instrumentation: direct mass measurement in real time. In addition, the Differential TEOM® monitor was designed to provide this real-time determination of the ambient PM mass at the temperature as it exists in the atmosphere at the time of collection. The goal of this work was to construct prototype Differential TEOM® monitors for field testing under uncontrolled ambient temperature operation of the monitor. The prototype monitors needed to be designed for sampling PM10 aerosol as well as PM2.5 aerosol.
Summary/Accomplishments (Outputs/Outcomes):
A prototype Differential TEOM® monitor was constructed and evaluated with regards to the thermal requirements of the design goals. During evaluation, the temperature of the sample measured with the monitor was within 5°C of the ambient temperature, meeting one of the major requirements of the design. Evaluation of the noise rejection of the prototype monitor also showed that the prototype was equivalent to the response of commercial instruments produced.The prototype monitor was field tested at the Albany, NY, facilities of Rupprecht & Patashnick, Co., Inc. (R&P). PM mass sampling by the prototype Differential TEOM® monitor showed significant progress in developing a new reference standard for ambient PM mass measurement. The results were compared with similar measurements of a controlled reference Differential TEOM® monitor operating at a fixed control temperature and with the results of Federal Reference Method (FRM) samples collected during the same sample period. The prototype Differential TEOM® monitor and the reference monitor showed excellent comparative results. Comparing the 24-hour results between the two TEOM® monitors and the FRM sample again showed good correlation between the samples. Previous testing has shown that the aerosol collected at the R&P facilities in Albany, NY, is primarily nonvolatile, except during the cold periods of December through January.
Conclusions:
Initial testing of the prototype system at the R&P facilities in Albany, NY, demonstrated that the Differential TEOM® monitor shows promise in being used as a reference standard for sampling PM from ambient air. By operating the monitor at ambient temperature, many of the limitations of conventional filter-based methods are addressed. The major benefit of the Differential TEOM® monitor compared to conventional filter-based methods is the ability to determine the ambient PM mass concentrations in real time rather than days or weeks after the sample was collected.All of the technical objectives originally defined in the Phase I proposal were met and lay an excellent foundation for a Phase II development and commercialization effort. The proposed Phase II work will include field testing at multiple locations and under widely differing ambient aerosol concentrations and chemical compositions.
Supplemental Keywords:
Differential TEOM®, self-referencing, particulate matter, PM sampling, ambient PM, particulate sampling, semivolatile, air sampling, tapered element oscillating microbalance, air monitor, SBIR, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Monitoring/Modeling, Environmental Monitoring, Ecology and Ecosystems, Atmospheric Sciences, ambient aerosol, atmospheric particulate matter, reference standard, ambient particle properties, atmospheric particles, particulate, direct mass measurement, aerosol composition, particulate matter mass, PM, aersol particlesSBIR Phase II:
An Innovative Sampler as a Reference Standard for Measurement of Particulate Matter Mass in Ambient Air | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.