There are many areas where the measurement of gas composition is essential – the determination of energy content of natural gas and other fuel gases, the measurement of stack emissions, or monitoring of air toxicities. In each area, quality gas calibration standards are the foundation of making correct measurements.
Gas calibration standards are used with gas analysis equipment to determine the composition of a gas sample. The National Measurement Institute (NMI) can develop specific gas calibration standards to address the particular needs of business and industry, including standards for the testing of conventional natural gas, LNG, and coal seam gas (CSG).
NMI’s Damian Smeulders says “The best way to make reliable and correct measurements of gas composition is to use quality gas standards from a reputable source, and to then confirm the accuracy of your measurements through participation in a proficiency testing study.”?
Proficiency testing (PT) studies operate by having gas samples of known composition sent to testing laboratories for analysis. The laboratory tests the sample and reports the gas composition that has been determined. The company is then shown the difference between its measured composition and the actual values.
PT participation ensures companies continue to work and report from a position of strength, based upon fact and knowledge. For companies that do not achieve the correct result, they can rectify an otherwise unknown fault possibly leading to improvements in their operations.
As the only provider of gas proficiency testing services in Australia, NMI is dedicated to partnering with Australian businesses to develop studies focused on local needs and emerging industries.
NMI has developed PT studies to support various industries, including safety measurements in underground coal mines; with BHP Billiton on the measurement of CSG; and with Santos in developing studies on both sales gas and raw natural gas.
Woodside and Santos, as well as pipeline operators such as APA Group, say their participation and achievement of excellent results in past studies on natural gas gave them independent endorsement and thereby confidence that they are making quality measurements and reporting factual results.
Woodside says that participation in the studies “helps us when we are audited by the National Association of Testing Authorities (NATA). NATA would like us to participate in as many round robins as possible.”?
Participation in PT studies is a quality system requirement that some may see as an unnecessary burden. However, NMI says that most laboratories gain real and lasting benefits as the studies are an independent, unbiased assessment on the quality of work they deliver.
Laboratories that participate are given comparative information on the processes, measurements and gas composition estimates used by their peers. In addition, confidentiality is maintained throughout each study, enabling participants to choose whether to inform clients about their performance.
Several participants in the recent PT study on CSG had problems with the measurement of the nitrogen in the gas sample. With NMI’s assistance, the participants were able to rectify these problems. Their participation was invaluable as it prevented the future reporting of incorrect results.
The next PT study will examine unprocessed natural gas with high CO2 content.