Flue gas Flue gas Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants. Its composition depends on what is being burned, but it will usually consist of mostly nitrogen (typically more than two-thirds) derived from the combustion of air, carbon dioxide (), and water vapor as well as excess oxygen (also derived from the combustion air). It further contains a small percentage of a number
Gas meter prover Gas meter prover A gas meter prover is a device which verifies the accuracy of a gas meter. Provers are typically used in gas meter repair facilities, municipal gas meter shops, and public works shops. Provers work by passing a known volume of air through a meter while monitoring the gas meters register, index, or internal displacement. The prover then displays a proof, a value expressed as a percent which compares the volume of air passed with the volume of air measured to determine the meters accuracy. Since the early 1900s, bell provers have been the most common reference standard