PD ISO/TR 12148:2009 PDF

1   Scope This Technical Report describes the principles of, and general requirements for, the traceable calibration of automatic hydrocarbon-dew-point chilled-mirror instruments using the indirect automatic weighing method (method B) described in ISO 6570:2001 to determine the potential hydrocarbon liquid content of natural gas, or similar gas. The calibration procedure is intended for use by chilled-mirror instruments in downstream applications transferring processed natural gas. If the gas composition is constant, the manual weighing method (method A) described in ISO 6570:2001 is also applicable.

NOTE 1 Whether or not a gas composition is constant is difficult to establish. A process gas chromatograph (GC) measuring calorific values within 0,1 % is absolutely no guarantee for a constant hydrocarbon liquid drop-out content. Information up to C 12 is required to verify that the gas composition is constant.