U.S. Environmental Protection Agency (EPA) regulations call for continuous emissions monitoring (CEM) systems to be tested with “zero-air” materials to qualify the accuracy of the instruments. CEMS operators sometimes mistakenly use a standard EPA protocol mixture as a zero gas, this company says, but doing so may not satisfy EPA acid rain requirements. Calibration gases from this company meet the strict definition of the term used in the regulations. Three types of zero-air materials (ZAM) are offered — air, nitrogen and oxygen — and they are guaranteed to be compliant with Part 75 of the regulations. Each ZAM product is analyzed and certified to meet the requirements for trace SO2, NOx, THC (total hydrocarbons), CO and CO2. The certified products eliminate the risk of faulty calibration of CEM systems due to biased zero readings, the company says. — Air Liquide USA, Houston
CEM standards that achieve regulatory compliance
| By Chemical Engineering