The Basics

A Master Meter is a simple flow meter. It is designed to test the calibration of LPG devices. A Master Meter is an LPG meter stripped of the vapor-eliminator and differential valve equipped with an inlet valve, outlet valve and a thermometer well in the discharge side.

Master Meters Vs. Volumetric Provers

Volumetric Provers are preferred but very expensive. It is for this reason that the Department supports the use of and certifies Master Meters. A Master Meter, when used properly, will verify the accuracy of commercial devices.

To Certify or Not to Certify -- That is the Question

The certification of a Master Meter is a function of the State's Metrology Laboratory, and must be certified to laboratory standards traceable to the National Institute of Standards and Technology (NIST). See more information about the Department's Metrology Laboratory.

How Can I Receive FREE Master Meter Training?

To help and encourage companies to utilize master meters to maintain their equipment, the Department offers free infield Master Meter training workshops once a year. Workshops are conducted during the month of May in Flagstaff.