How to use and safety precautions of multi-purpose clamp meter
(1) When using a clamp meter, the size of the measured current should be estimated first and the appropriate range should be selected. Generally, a larger range should be selected first, and then adjusted to the appropriate range depending on the magnitude of the measured current.
(2) To ensure the correct reading of the clamp gauge, after the wire is clamped into the clamp, the two sides of the clamp iron core should match well.
(3) The jaws of a clamp meter can only hold one wire, and if two wires are clamped in, the current in the wires cannot be measured.
(4) After each measurement of the clamp meter, the range conversion switch should be placed in the maximum range position to prevent others from using the instrument without selecting the range and damaging it.
The working principle of a clamp type meter is the same as that of a transformer. The primary coil is a wire that passes through a clamp type iron core, equivalent to the primary coil of a 1-turn transformer, which is a step-up transformer. The secondary coil and the ammeter used for measurement form a secondary circuit. When an alternating current passes through a wire, it is this coil that generates an alternating magnetic field, causing an induced current in the secondary circuit. The ratio of the current to the primary current is inversely proportional to the number of turns in the primary and secondary coils. Clamp type ammeter is used to measure high currents. If the current is not large enough, the primary wire can be passed through the clamp type ammeter by increasing the number of turns, and the measured current can be divided by the number of turns.
