How to Calibrate Clamp Meter-Equivalent Ampere-Turn Method

1. What is Clamp Meter

A clamp meter is an electrical testing tool that integrates a basic digital multimeter with a current sensor. Clamps measure current. Probes measure voltage.

Clamp meters are mainly used to test electrical parameters such as voltage, current, and power. In addition, clamp meters can be used to test the following electrical parameters: AC and DC current, voltage, power, AC frequency, DC resistance, temperature and capacitance

The difficulty in improving the calibration accuracy of the clamp meter lies not in the accuracy of the current source, but in the uniformity and accuracy of the magnetic field generated by the wire under test.

Experiments on clamp meter ring diameters ranging from 10mm to 100mm have shown that when the length of the current-cutting wire reaches 1 meter, the system error of the straight wire portion of the clamp meter ring of all diameter specifications can be reduced to within -0.5%.

TUNKIA uses the standard source method to test clamp meters. The standard source method is often divided into single-turn method and equivalent ampere-turn method.

3. Equivalent Ampere-Turn Method

Using the TUNKIA’s TD18 series Multi-function Calibrator with the TD1020 Current Coil, the user can choose the TD1020 Current Coil (50 turns) and pass in the AC and DC standard current of 20 A to achieve an equivalent current output of up to 1000 At, which is suitable for calibrating lower accuracy clamp meter or current clips of accuracy 1% and below.

• Equivalent current output: 1000 A

• Maximum current input: 22 Arms

• Coil ampere-turns: 50 turns

• DC measurement uncertainty: 0.3%

• AC measurement uncertainty: 0.3%@50Hz, 0.5%@400Hz

• Working frequency: DC, 45～400 H

For calibrating higher-precision clamp meters, you can choose TUNKIA's TD1000 and TD1050 Clamp Meter Calibration Device.

4. Operation Demo of Using TD1870+TD1020 to Test Clamp Meter