Usage and precautions of clamp ammeters
The clamp type AC ammeter mainly consists of current transformers and rectifier system instruments. The measured current carrying conductor is equivalent to the original winding of the current transformer. On the iron core is the secondary winding of the current transformer. The secondary winding is connected to the rectifier system instrument. According to a certain proportion of variation between the primary and secondary windings of the current transformer, the rectifier instrument displays the current value of the tested circuit.
The clamp type AC/DC meter is an electromagnetic instrument. The measured current carrying wire is placed in the clamp as the excitation coil. The magnetic flux forms a circuit in the iron core. The electromagnetic measurement mechanism is located in the middle of the iron core gap and is deflected by the magnetic field to obtain readings. Since its deflection is not affected by the measurement current, it can measure AC and DC currents.
Usage of clamp ammeter
When measuring current, simply clip the wiring to be measured into the core of the clamp type ammeter, and then read the reading on the digital display screen or indicator board. It is easy to use. Just clamp the measuring line tightly. However, with the widespread use of digital clamp ammeters, clamp ammeters have added many functions such as voltage, temperature, resistance, etc. (sometimes referred to as clamp multimeter, as shown in the right figure, with two probe sockets on the instrument). By turning the button, different functions can be selected, and the usage method is similar to that of a regular digital multimeter. Please refer to the corresponding instructions for the meanings of some special function buttons.
When using a clamp type ammeter, the following issues should be noted:
When the measured current is small, the current carrying wire can be wound several times and placed in the clamp for measurement. However, the actual current value can be obtained by dividing the reading by the number of coils. After the measurement is completed, place the adjustment switch in the maximum range position (or closed position) for safe use next time.
Do not switch gears during measurement.
Pay attention that the voltage on the circuit should be lower than the rated value of the clamp ammeter. Clamp ammeters cannot be used to measure the current of high-voltage circuits, otherwise it may cause accidents or electric shock.
