Testing Revenue Meters

The most common application of electric energy standards is the accuracy testing of revenue billing meters. There are five primary components required for testing a revenue meter. They are:

Reference Standards: The reference standard is the heart of the accuracy test. It is the reference measurement to which the meter's energy measurement is compared. It is important to utilize a reference standard with an accuracy that is significantly better than the meter you are testing. If the standard that you use is only slightly more accurate than the meter under test, the validity of your test on that meter becomes questionable.

Current Source or Phantom Load: A current source or Phantom Load is used to generate the test current for the meter test. Both the reference standard and the meter under test must have the exact same voltage and current signal applied. Voltage and current sources are available in both portable configurations for field testing and in larger stationary configurations for laboratory or meter shop applications. Customers typically maintain phantom loads from old test sets and upgrade the remaining components.

Sensors and Pickups: Sensors and Pickups are used to automate the timing of a meter test. These devices "sense" a calibration pulse from a revenue meter. There are many different types of sensors suited for testing electromechanical induction meters and electronic meters.

Counters and Comparators: A counter automates meter testing by counting pulses from a sensor for a specified test length. After counting the set number of pulses, the counter typically stops the standard's display allowing the user to calculate the accuracy of the meter under test. A comparator will also count calibration pulses from the reference standard and in many instances performs an automated calculation of meter accuracy.

Universal Test Jack: The universal test jack is typically required only with ANSI style socket based meters. The test jack allows the user to properly route the voltage and current signals from the phantom load so that the meter under test is properly powered. A test jack of this type is not required with bottom connect meters which have a more straightforward connection of voltage and current signals. New Universal Test Jacks are available from Ekstrom Industries.

Testing Singlephase Revenue Meters: For testing singlephase, self-contained, ANSI- style socket meters Radian offers Portable Test Systems. These portable test systems contain all five of the components for meter testing in a lightweight, compact, simple to operate test kit.