Summary of correct use of clamp Ammeter
1. Prohibit measuring uninsulated wires
Clamp Ammeter is directly used to measure the electrical equipment in operation. When carrying a clamp Ammeter on a live line, you must be very careful not to measure uninsulated conductors.
2. Choose the appropriate range
Before measurement, the magnitude of the measured current should be estimated and an appropriate range should be selected.
If it is impossible to estimate, first measure with a larger range, and then gradually switch to a suitable range based on the magnitude of the measured current.
During each range change, the jaw must be opened, and then the range switch must be changed. The jaw of the clamp Ammeter must be kept clean and dry.
3. Zeroing
Before measurement, if it is a pointer type meter, check whether the pointer of the Ammeter points to the zero position. Otherwise, carry out mechanical zero adjustment to improve the accuracy of the reading.
4. Opening and closing of jaws
Before measurement, the opening and closing of the jaws should also be checked.
(1) The movable part of the jaw should open and close freely, and the two joint surfaces should be tight to reduce magnetic flux leakage and improve measurement accuracy;
(2) When there is vibration or collision sound when the wire is clamped into the clamp, the instrument handle should be turned a few times or opened and closed again until there is no noise before reading the current value.
5. Measure small current
Place the measured current carrying wire in the center of the clamp during measurement to avoid any increase in error.
When the current of the circuit being measured is small, in order to make the reading more accurate, the current carrying wire being measured can be wrapped around the iron core column in the clamp part for several turns before measurement. The actual current value is equal to the reading of the instrument divided by the number of turns of the wire placed in the clamp.
