5.1 This test method provides an accurate and reliable procedure to measure the total heating value of a fuel gas, on a continuous basis, which is used for regulatory compliance, custody transfer, and process control.

5.2 Some instruments which conform to the requirements set forth in this test method can have response times on the order of 1 min or less and can be used for on-line measurement and control.

5.3 The method is sensitive to the presence of oxygen and nonparaffin fuels. For components not listed and composition ranges that fall outside those in Table 1 and Table 2, modifications in the method and changes to the calibration gas or gasses being used may be required to obtain correct results.

(A) Flare Gas Heating Value range defined in Table 2 is derived from the Evaluation of the Efficiency of Industrial Flares: Flare Head Design and Gas Composition EPA-600 /2-85-106 September 1985 Table 1-1. Agency Information Collection Activities OMB Responses EPA ICR Number 2411.01; NSPS and NESHAP for Petroleum Refineries Sector Residual Risk and Technology; OMB Number 2060-0657.(B) A CAS Registry Number is a unique identification number, assigned by the Chemical Abstracts Service (CAS) in the US to every chemical substance described in the open scientific literature, in order to index the substance in the CAS Registry.