Zero Gases for Emission Monitoring - Production, Storage, Treatment and Usage

Increasingly stringent emission levels require better quality facility gas supplies to enable more precise measurements at low levels and reduce variation in test results. The transient and steady state quality of the “zero gas” used in analyzer calibration will directly affect the level of the readings, while variation in the “zero gas” over time will increase the number of tests needed to meet statistical requirements.

Facility zero gas supplies for air and nitrogen, at a minimum, require careful evaluation to confirm that the required gas quality is delivered to the test equipment for the desired instrument accuracy. To move from LEV or ULEV to SULEV analysis, a change in methodology of zero gas generation, delivery and handling may be needed to achieve the desired measurement accuracy and repeatability.

Traditional tubing, fittings and handling methods can not only limit the possible gas quality, but also contribute to variation. This review identifies the considerations for equipment and process (as well as tools to generate a cost of ownership study) needed to deliver the desired gas quality for house air and nitrogen.