9 ways to use a clamp meter
1. Read the instruction manual carefully before use to find out whether it is an AC or AC/DC dual-purpose clamp meter. Select the clamp ammeter correctly according to the type and voltage level of the current being measured.
2. Before use, check whether the appearance, jaw closing and meter head of the clamp ammeter are normal. If the pointer is not at zero, mechanical zero adjustment should be performed.
3. Before measuring, you should first estimate the size of the current being measured, and then decide which range to use. If it is impossible to estimate, you can use the maximum range first, and then change it to a smaller range appropriately so that you can get accurate readings. Do not use the small current range to measure large currents to prevent damage to the instrument.
4. Since the accuracy of the clamp ammeter itself is low, when measuring small currents, the following method can be used: first wind the wire of the circuit under test several times, and then put it into the jaws of the clamp meter for measurement. At this time, the current value indicated by the clamp meter is not the actual value being measured. The actual current should be the reading of the clamp meter divided by the number of turns of the wire.
5. The jaws of the clamp meter should be closed tightly during measurement. If there is noise after closing, open the jaws and close them once. If the noise still cannot be eliminated, check whether the joint surfaces on the magnetic circuit are smooth and clean, and wipe them clean if there is dust. .
6. The clamp meter measures the current of the wire, and the wire to be measured should be placed in the center of the clamp.
7. The voltage of the circuit under test cannot exceed the value indicated on the clamp meter, otherwise it may easily cause a grounding accident or cause an electric shock hazard.
8. When measuring the motor current, you can measure once for each phase or once for three phases. At this time, the number on the meter should be zero. When there are two phase wires in the jaw, the value displayed on the meter is the current value of the third phase. , by measuring the current of each phase, it can be judged whether the motor is overloaded, whether there is a problem inside the motor or the power supply voltage, that is, whether the three-phase current imbalance exceeds the 10% limit.
9. After reading, open the jaws, withdraw the wire under test, and set the gear to the highest current level or OFF gear.
