Natural gas meter prover and meter proving
A natural gas meter prover is a piece of equipment that verifies a gas meter is accurate. While various types of gas meters require meter proving, here we focus on the diaphragm gas meter.
What is a meter prover?
Diaphragm meters measure gas flow volume in the natural gas distribution for residential and commercial applications. This meter style is a proven technology with over 100 years of application service and offers excellent value with a typical life expectancy of 25 years. The data the meter generates is collected and used to bill customers. For this reason, from time to time it is desired to verify the accuracy of these meters.
Traditional provers are usually kept at meter shops or repair facilities where meters are sent to verify their accuracy. Alternatively, there are some in-situ or onsite provers that can verify a meter’s accuracy in the field which can save time and money in the long run.
Provers compare a known amount of air flowing across a meter and through mathematical calculations produce a numeric value which reflects a “proof” of its accuracy.
There are three types of provers used to verify accuracy of diaphragm gas meters:
A transfer prover is a portable proving system that was originally developed for field testing. By identifying meters while they are still in the field, the user can test and adjust them onsite which will save money. Additionally, some companies are using transfer provers in their meter shops to supplement the existing facility equipment.
The manual bell prover has been commonly used in many gas industry reference standards since the early 1900s. Unfortunately, operator inaccuracies made this highly susceptible to inaccuracies. With the development of programmable logic controllers however, this device was automated to remove the human factor and remains a common device to calculate meter proof.
Sonic Nozzle Prover
The sonic nozzle is an advanced technology that operates using constant volumetric airflow at the speed of sound. This is generally a fully automated system that is PC driven to operate the prover and integrate the data.
Natural gas meter provers have been used to verify the accuracy of gas meters since the early 1900s.