Clamp ammeter use and precautions
Clamp-on AC ammeters are mainly composed of current transformers and rectifier system instruments. The measured current-carrying conductor is equivalent to the primary 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 the current transformer primary winding and the secondary winding between a certain proportion of change, by the rectifier instrumentation to display the current value of the circuit under test.
Clamp-type AC and DC meter is a kind of electromagnetic type instrument. The measured current-carrying wire is placed inside the jaws as an excitation coil. The magnetic flux forms a circuit in the iron core. The electromagnetic measuring mechanism is located in the middle of the core gap and is deflected by the magnetic field to get a reading. Since its deflection is not affected by the measuring current, it can measure AC and DC currents.
How to use the clamp-on ammeter
To measure current, simply clamp the alignment to be measured inside the core of the clamp-on ammeter and take a reading on the digital display or indicator board. It is easy to use. Just clamp the measuring wire. However, with the widespread use of digital clamp-on ammeters, many functions have been added to the clamp-on ammeter, such as voltage, temperature, resistance, etc. (sometimes referred to as a clamp-on multimeter, as shown in the photo to the right, with two probe sockets on the instrument). Different functions can be selected by turning the buttons, and the use is similar to that of an ordinary digital multimeter. For the meanings of some special function buttons, please refer to the corresponding descriptions.
Clamp the current-flowing wires to adjust the appropriate measuring range.
The following issues should be noted when using the clamp-on ammeter:
When the current to be measured is small, the current-carrying wire can be wound several times and placed in the jaws for measurement. However, the actual current value can be obtained by dividing the reading by the number of coils. When the measurement is complete, place the adjustment switch in the maximum range position (or off position) for safe use next time.
Do not switch gears during the measurement.
Note that the voltage on the circuit should be lower than the rated value of the clamp-on ammeter, and the clamp-on ammeter should not be used to measure the current in a high-voltage circuit, as this may easily cause accidents or electric shock.
