ABSTRACT
Custody transfer is being based upon the heating value of the gas as well as the volume. Consequently, the on-line gas chromatograph or BTU analyzer is becoming an increasingly important instrument in the industry. The gas chromatograph is not only capable of meeting the needs for on-line applications but also provides several additional features. Technological advancements in both micro-packed columns and microprocessors have allowed the development of very powerful and flexible on-line gas chromatographs. Measuring the energy content of natural gas in an online fashion requires a self-contained instrument that is programmable and rugged. A comparison of the calorimeter with an on-line gas chromatograph indicates that the calorimeter is capable of equivalent accuracy to that of the chromatograph, but is much slower to respond. The on-line gas chromatograph has become a viable tool in the industry for measuring BTU content of natural gas.
