In this topic, you study Calibration of Energy Meter – Definition, Procedure & Diagram.
By calibration of the energy meter, we mean that the meter should read 1 kWh if 1000 W (1 kW) load is operated for an hour.
Calibration of Single Phase Energy Meter (By Direct Loading Method)
The circuit diagram for calibration of the energy meter is shown in Fig. 1. The load of 1 kW is put on the energy meter. To enable to check the energy meter, at various loads and time, usually 10 lamps of 100 W each is used.
Fig. 1. Calibration of Single Phase Energy Meter.
First of all reading of energy meter is brought at zero. Now the total load of 10 lamps is operated for one hour (by using a stopwatch). After 1 hour, the energy meter should show consumption of 1unit. (i.e., 1 kWh). If not so, the meter is adjusted accordingly. The above procedure is repeated at different loads and times, and the process of calibration is completed.