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AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF TWO HYDROGEN SULFIDE ANALYZERS: HORIBA INSTRUMENTS, INC., APSA-360 AND TELEDYNE-API MODEL 101E
Citation:
BATTELLE MEMORIAL INSTITUTE, A. L. SUMNER, A. DINDAL, Z. WILLENGERG, AND K. RIGGS. AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF TWO HYDROGEN SULFIDE ANALYZERS: HORIBA INSTRUMENTS, INC., APSA-360 AND TELEDYNE-API MODEL 101E. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-05/126 (NTIS PB2006-101284), 2005.
Impact/Purpose:
The overall objective of the ETV Program is to accelerate the entrance of new environmental technologies into the domestic and international marketplace by identifying the environmental performance characteristics of commercial-ready technology through the evaluation of objective and quality assured data. This provides the potential purchasers and permitters with an independent and credible assessment of what they are buying and/or permitting. The AMS Center has received funding to performance verify monitoring technologies relevant for homeland security.
Description:
The Environmental Technology Verification (ETV) Program, beginning as an initiative of the U.S. Environmental Protection Agency (EPA) in 1995, verifies the performance of commercially available, innovative technologies that can be used to measure environmental quality. The ETV provides, through a third-party, quality-assured performance data so buyers and users of environmental technologies can make informed purchase and application decisions, thus providing one path to reducing emissions and improving human health. To provide cost-effective testing, Stakeholder committees, made up of members with diverse backgrounds, provide guidance with identifying and prioritizing environmental technologies to address present day environmental quality challenges.
The ETV Advanced Monitoring Systems (AMS) Center, one of six ETV Centers, is actively involved in verifying the performance of advanced monitoring systems available to the public for purchase. The AMS Center participates in the mission of the ETV by providing Test Plans, Protocols, conducting independent performance tests of technologies, and preparing Verification Reports and Statements describing the results of the testing. Vendors of tested technologies can use the Verification Reports and Statements for marketing purposes. All approved Verification Reports are posted on the ETV Web Site as a form of public distribution. The individual verification reports and statements describe by this abstract are fora Horiba Instruments, Inc. Model APSA-360 and a Teledyne-API Model 101E ambient hydrogen sulfide analyzers.
The objective of this verification test was to evaluate each analyzer's performance in measuring gaseous H2S in ambient air at an animal feeding operation (AFO). The verification test was conducted for six weeks between April 25 and June 3, 2005, at a swine finishing farm near Ames, Iowa. This site was selected to provide realistic testing conditions and was expected to exhibit a wide range of H2S concentrations during the test period. The verification test was designed to evaluate accuracy, bias, precision, linearity, span and zero drift, response time, interference effects, comparability, data completeness, and operational factors.
The analyzer's response to a series of H2S gas standards was used to evaluate accuracy, bias, precision, and linearity. Each gas standard was delivered in triplicate, and the series of gas standards were delivered three times during the verification test. Accuracy was calculated at each concentration and for each replicate relative to the nominal H2S concentration. Bias was calculated for each series of multipoint H2S challenges. Precision was demonstrated by the reproducibility of the analyzer's response at each nominal H2S concentration. Linearity was assessed by establishing a multipoint calibration curve from each analyzer's response. The baseline response of each analyzer to zero air and a 30-parts per billion (ppb) dilution of a compressed H2S gas standard was determined during the first week of testing. At least twice each week, zero air and a 30-ppb H2S standard again were supplied to the analyzer for 20 minutes for a total of 14 zero/span checks. Each response was compared to the Week 1 baseline response to determine whether drift occurred in the response to zero air or the 30-ppb H2S standard. The data collected during the two zero/span baseline response checks were used to determine the analyzer's response time. To determine interference effects, each analyzer was challenged with a series of gases (supplied at either 100 or 500 ppb in the presence and absence of 100 ppb of H2S) that may be present at an AFO and could interfere with the analyzer's response to H2S. The comparability of each analyzer's response to ambient air was evaluated by comparing its response to two H2S reference methods (time-integrated and in situ), which were carried out by the U.S. Department of Agriculture (USDA) and Applied Measurement Science. The two reference methods were based on American Society of Testing Materials (ASTM) Method D5504-01, with pulsed flame photometric detection substituted for sulfur chemiluminescence detection. Data completeness was assessed based on the overall data return achieved by each analyzer. Operational factors such as maintenance needs, data output, consumables used, ease of use, and repair requirements were evaluated based on the observations of Battelle and USDA staff.
QA oversight of the verification testing was provided by the EPA and Battelle. Battelle QA staff conducted a technical systems audit and a data quality audit of 10% of the test data. The verification statement, the full report on which it is based, and the test/QA plan for this verification are all available at http://www.epa.gov/etv/centers/center1.html.