The purpose and working principle of clamp ammeters
Working principle: A clamp meter is composed of a current transformer and an ammeter. The iron core of the current transformer can be opened when the wrench is tightened; The wire through which the measured current passes can pass through the open gap of the iron core without cutting it off. When the wrench is released, the iron core closes.
The tested circuit wire passing through the iron core becomes the primary coil of the current transformer, where the current is induced in the secondary coil through the current. Thus, the ammeter connected to the secondary coil has an indication - to measure the current of the tested circuit.
Usage: When measuring current with a regular ammeter, it is usually necessary to cut off the circuit and shut down before connecting the ammeter for measurement. This is very troublesome, and sometimes normal running motors are not allowed to do so. At this point, using a clamp type ammeter becomes much more convenient, as it can measure current without cutting off the circuit.
Extended Information
The clamp meter can be changed to different ranges by shifting the gears of the switch. However, it is not allowed to operate with power when shifting gears. The accuracy of clamp shaped watches is generally not high, usually ranging from 2.5 to 5 levels. For ease of use, there are also conversion switches with different ranges in the meter for measuring different levels of current and voltage.
The clamp meter was originally used to measure AC current, but now it also has functions such as measuring AC and DC voltage, current, capacitance, diode, transistor, resistance, temperature, frequency, and so on.
Clamp type ammeters can measure photovoltaic DC current and inverter output AC current. It should be noted that some clamp type ammeters do not have DC function, and the clamp mouth should be tightly closed and cannot be changed with power.
