In the Report of Analysis: Environmental Protection Agency Blind Audit 2013, the National Institute of Standards and Technology (NIST) analyzed 240 calibration gases between 2013 and 2015. The mixtures were tri-blends of carbon dioxide (CO2; range: 5% mol/mol – 20% mol/mol); nitric oxide (NO; range: 25 µmol/mol – 1000 µmol/mol (ppm) and total oxides of nitrogen, NOX, within 1% relative of NO) and sulfur dioxide (SO2; range : 50 µmol/mol – 1000 µmol/mol (ppm)).
The 2013 audit of EPA protocol gases found a 2.1% failure rate over all components analyzed, with 15% of the production sites failing at least one gaseous component. The Report of Analysis: Environmental Protection Agency Blind Audit 2013 was compiled by NIST and released on April 21, 2015.
2013 Results at a Glance
|Number of Samples||240|
|Number of Failures||5|
|Number of Production Sites||20|
|Number of Production Sites that Failed||4|
|Percent of Production Sites that Failed||20%|
|Number of Participating Vendors||11|
|Number of Vendors that Failed||4|
|Percent of Vendors that Failed||36%|