Explanation of the working principle from the internal structure of the clamp-on ammeter
Clamp meter mainly consists of an electromagnetic ammeter and through-centre current transformer. Through the core type current transformer vice side winding winding in the core and connected with the AC ammeter, its original side winding is through the centre of the transformer for the measured wire. Measurement of current, press the spanner, open the jaws, the measured current-carrying wires placed in the middle of the wear-centre type current transformer, when the measured wires in the alternating current through the AC current flux in the transformer vice-side windings induced by the current, the current through the electromagnetic ammeter coils, so that the pointer is deflected, in the dial scale pointed out that the measured value of the current. The clamp-on ammeter must be connected in series with the circuit under test.
In practice, it is necessary to disconnect the line, obviously very inconvenient. Clamp clamp ammeter is a do not need to disconnect the circuit can be directly measured circuit AC current portable instrumentation, electrical maintenance in the use of very convenient, quite widely used.
Clamp meter knob is actually a range selector switch, the role of the spanner is to open and close through the core of the core transformer movable part, in order to make it clamp the measured wire.
Clamp ammeter in the application of high-voltage systems
1, applicable to 60KV and below the measurement of high and low voltage system, test high voltage using protective insulating rod sets of detection; for 600V or below the low-voltage system, you can use the high-voltage clamp meter to directly test the line AC current, leakage current is equivalent to a high-precision low-voltage ammeter.
2, the measurement of high-voltage system line current measurement, online current measurement, but also has a peak hold, data retention, storage, wireless transmission and other functions, its special clamp ammeter by pressing or pulling back the insulating rod can be convenient to clamp or evacuation of the measured wire.
3, can be used as high and low voltage current transformer ratio tester, zinc oxide lightning arrester tester. High precision clamp meter, the minimum range of 10 microamps.
High-voltage clamp-on ammeter is an indispensable instrument for measuring the current value of high-voltage lines, so it is necessary to maintain the instrument regularly. And test high-voltage personnel must be in accordance with the operating procedures and obtain the relevant national high-voltage operating certification to carry out on-site testing!
