How to take care of a clamp-on ammeter
A clamp ammeter is an instrument used to measure the current of an operating electrical circuit, which can directly measure the working current of the equipment in operation without disconnecting the power and circuit. In addition, it can also measure AC and DC voltage, resistance, and pass tests.
(1) Precautions for using clamp ammeters
① Before measurement, the initial measurement current should be estimated and an appropriate range should be selected.
② The measured current carrying wire should be placed at the center of the clamp during measurement to avoid errors. For the measurement of wires with less current, in order to improve accuracy, if conditions permit, the measured wire can also be wound a few more turns and then placed in the clamp for measurement. The actual current value is equal to the instrument reading divided by the number of wire turns.
③ If there is noise during the measurement process, it is due to poor contact between the pliers and the wire. The pliers can be opened and closed again. If the noise still exists, the pliers can be cleaned with gasoline before measurement.
(2) Measurement operation method
① AC power measurement. Turn the switch to the ACA1000A position. Keep the switch in a relaxed state. Press the trigger to open the jaws, clamp a wire, and read the value. If the reading is less than 200A, the switch should be turned to ACA200A to improve the accuracy of the reading.
② Measurement of AC and DC voltages. When measuring DC voltage, turn the switch to DCV1000 gear. When measuring AC voltage, turn the switch to ACV750V gear and keep the switch in a relaxed state. Connect the red probe to the "V Ω" terminal and the black probe to the "COM" terminal, and then connect the red and black probes in parallel to the tested circuit. The value read is the actual voltage of the circuit.
③ Measurement of resistance. Turn the switch to the appropriate range of resistance. Keep the switch in a relaxed state. Connect the red probe to the "V Ω" end and the black probe to the "COM" end. Connect the red and black probes to both ends of the measured resistance, and the value read will be the actual resistance value of the measured resistance.
Attention: When measuring the online resistance, the circuit should be powered off and the capacitor connected to the resistance should be discharged.
④ On/off testing. Turn the switch to the 200 Ω position, connect the red probe to the "V Ω" end and the black probe to the "COM" end. If the buzzer inside the meter sounds, it indicates that the resistance between the red and black probes is less than 50 ± 2.5 Ω.
