There’s a great article in this month’s Power Engineering magazine:
“Proper Calibration of Gas Analyzers” by Terrence Kizer.
(October 2010, starts on page 22)
It points out some of the options for CEMS calibration gas cylinders and how the analyzers use them to monitor for analyzer drift.
You should also check on your natural gas chromatograph calibration gas cylinders (if you have an onsite chromatograph) – the closer the calibration gas is to your actual pipeline gas, the more accurate the resulting analysis will be. If you’re still using the same calibration gas determined during site development, you might want to take a second look. Pipeline gas can shift from season to season, and if your calibration gas is significantly different than actual, the accuracy of the reported heating values will be affected.
If your chromatograph is also used for billing purposes – you’ll want to make double sure the calibration gases are correct. Even a 0.2% increase in a plant fuel bill can be a very large number!