A clamp meter (clamp meter) is an instrument that integrates a current transformer and an ammeter. Its working principle is the same as that of a current transformer to measure current. The 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 opening of the iron core without cutting it, and the iron core is closed when the wrench is released. The circuit wire under test passing through the iron core becomes the primary coil of the current transformer, in which the current is induced in the secondary coil by passing the current. So that the ammeter connected to the secondary coil will have an indication-----measure the current of the line under test. Structure and principle The clamp meter is essentially composed of a current transformer, a clamp wrench and a rectifier magnetoelectric system with reaction force meter.
The working principle of a clamp meter is the same as that of a transformer. The primary coil is the wire passing through the clamp core, which is equivalent to the primary coil of a 1-turn transformer, which is a step-up transformer. The secondary coil and the ammeter for measurement constitute the secondary circuit. When an alternating current passes through the wire, it is this turn of the coil that generates an alternating magnetic field and induces an induced current in the secondary loop. The ratio of the current to the primary current is equivalent to the inverse ratio of the turns of the primary and secondary coils. . The clamp-type ammeter is used to measure large currents. If the current is not large enough, the primary wire can be passed through the clamp-type meter to increase the number of turns, and at the same time divide the measured current by the number of turns.
The secondary winding of the feedthrough current transformer of the clamp ammeter is wound on the iron core and connected to the AC ammeter, and its primary winding is the measured wire passing through the center of the transformer. The knob is actually a range selection switch, and the function of the wrench is to open and close the movable part of the iron core of the through-core transformer, so as to make it clamp the conductor under test.
When measuring the current, press the wrench, open the jaws, and place the measured current-carrying wire in the middle of the through-core current transformer. A current is induced in the side winding, and the current passes through the coil of the electromagnetic ammeter to deflect the pointer and indicate the measured current value on the dial scale.
The clamp meter is an instrument that integrates the current transformer and the ammeter, and its working principle is the same as that of the current transformer to measure the current. The 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 opening of the iron core without cutting it, and the iron core is closed when the wrench is released. The circuit wire under test passing through the iron core becomes the primary coil of the current transformer, in which the current is induced in the secondary coil by passing the current. So that the ammeter connected to the secondary coil will have an indication-----measure the current of the line under test.
The clamp meter can be changed to different ranges through the shift of the switch. However, it is not allowed to operate with power on when shifting gears. The accuracy of the clamp meter is generally not high, usually 2.5 to 5. For the convenience of use, there are also switches of different ranges in the meter for measuring different levels of current and measuring voltage.
The clamp meter was originally used to measure AC current, but now the multimeter has all the functions, which can measure AC and DC voltage, current, capacitance, diode, triode, resistance, temperature, frequency, etc.
