Calibration is the process of checking the accuracy of an instrument or measurement system by comparing its readings with a known, reference standard. In other words, calibration verifies the correctness of the instrument by comparing its output to the reference value. It helps identify any errors in the instrument’s readings and allows for adjustments to ensure the instrument provides accurate and ideal measurements.

where,
T = Test value
S = Standard value

Calibration of voltmeter :

Calibration of Voltmeter is the process of checking the accuracy of the reading of the Voltmeter under test (V_t) by comparing it with the standard Voltmeter (V_s) one. In other words, calibration checks the correctness of the instrument by comparing it with the reference standard.

where,
V_t = Test value
V_s = Standard value


Figure 1.0 Calibration of an AC voltmeter

Calibration of ammeter :

Calibration of Ammeter is the process of checking the accuracy of the reading of the ammeter under test (A_t) by comparing it with the standard Ammeter (A_s) one. In other words, calibration checks the correctness of the instrument by comparing it with the reference standard.


where,
A_t = Test value
A_s = Standard value


Figure 1.1 Calibration of an AC ammeter