Clamp Meters rely on the principle of magnetic induction to make non-contact AC current measurements. Electric current flowing through a wire produces a magnetic field. Since alternating current frequently reverses polarity, it causes dynamic fluctuations in the magnetic field which are proportional to the current flow. A current transformer senses the magnetic fluctuations and converts the value to an AC current reading. This type of measurement is convenient for measuring very high AC currents.
Direct current (DC), however, flows through conductors in a fixed polarity. DC clamp meters work on the principle of the Hall Effect. The magnetic field caused by current flow causes a small voltage across the Hall Effect sensor. That voltage which is proportional to current, is then amplified and measured.
Clamp Meter Features
Clamp meters are often available with a number of features such as True RMS the ability to read voltage, resistance. Higher end clamp meters are more likely to include these advanced functions. True RMS: Since alternating current reverses directions several times per second, it is represented as a sine wave. Because the amplitude of the sine wave changes continuously over the wave period, current measurements may vary quite a bit at different points in time. True-RMS (root mean square) converts AC signals into DC signals of equivalent value for more stable and accurate AC readings.
Considerations When Purchasing a Clamp Meter
- DC current measurement?
- Voltage AC / DC measurement?
- Resistance measurement?
- Earth Leakage measurement?
- Earth Resistance measurement?
- Consider the cable size you will encounter.
- Consider the maximum current and voltage you will want to read.
We offer clamp meters from Fluke, Martindale, Kewtech, Megger and Chauvin Arnoux
Please contact us if you require any assistance.