Types of Meter Test
A meter should pass the subsequent two types of tests:
Meters are calibrated such in which the whole accuracy is inside the percentage error limits. All initial calibrations of meters are performed in a laboratory or test house. The most general method for testing meters is to inject voltage and current from a stable power source in combination along with a reference meter. The main need in a test lab will be: Test bench, Reference standards, Power source, Software and Accessories.
Figure: Test Bench
The test bench could be for single phase or three phase meters, electromechanical or electronic. It could be fully automatic, semi automatic or manual. The meters in service required to keep to the prescribed accuracy range. With time the accuracy of the Ferrari's meter degrades and the meter tends to slow down. For that, periodical testing of and recalibration of all meters installed in the field for all categories of consumers required to be carried out as per the meter standards.