Types and uses of clamp ammeters
1. AC clamp ammeter
The AC clamp ammeter is composed of a current transformer and a rectifier ammeter. When the wrench of the clamp meter is tightened, the iron core of the current transformer is opened, and it is used to cover the measured current wire, and then the wrench is released. The wire is used as the primary winding of the current transformer, and on the iron core is the secondary winding of the current transformer, and the secondary winding is connected to a magnetoelectric ammeter through a rectifier. According to a certain transformation ratio relationship between the primary and secondary windings of the current transformer, the rectifier system instrument can display the current value of the line under test. By switching the switch to change the transformation ratio of the current transformer, different ranges from one ampere to tens of thousands of amperes can be obtained.
2. AC and DC dual-purpose clamp current
The shape of AC and DC dual-purpose clamp ammeter is similar to that of AC clamp ammeter, and it is composed of electromagnetic system measuring mechanism. When the measured current wire is clamped, a magnetic field is generated in the iron core, and the moving iron piece of the measuring mechanism located in the gap of the iron core is deflected by the magnetic field to drive the pointer. Its working principle is similar to that of the electromagnetic system instrument, so it can be used to measure AC Current can also be used to measure DC current.
3. Multipurpose clamp ammeter
The multi-purpose clamp ammeter is composed of a clamp transformer and a multimeter. When the connection line of the transformer is pulled out, the jaws do not work and can be used as a multimeter.
Second, the use of clamp ammeter
1. Choose the appropriate range gear. You cannot use a small range gear to measure large currents. If the measured current is small, you can wind the current-carrying wire a few more times and put it into the jaws for measurement. The reading should be divided by the number of coils. is the actual current value. After the measurement, put the transfer switch in the maximum range position (or off position) for safe use next time.
2. Do not switch the range gear during the measurement, so as not to bend the hands of the watch; if you need to change gears, you should first withdraw the measured wire from the jaws and then change gears.
3. Note that the voltage on the circuit should be lower than the rated value of the clamp ammeter. Do not use a clamp ammeter with a low voltage level to measure the current of the high voltage circuit, otherwise it will easily cause accidents or cause electric shock danger.
4. In thunderstorm days, it is forbidden to use clamp ammeter to measure outdoors.
