7 ways to use the clamp ammeter and 6 precautions
(1) Use of clamp ammeter
①The accuracy level of the clamp ammeter is not high, and it is often used in occasions where the measurement requirements are not high.
②Before measurement, the corresponding measurement range should be selected according to the current of the circuit under test; when the current of the circuit under test is difficult to estimate, the range switch should be set to the maximum measurement range.
③ There are usually multiple scales on the dial of the clamp ammeter, and the scale corresponding to the range of the range switch should be selected when measuring.
④ The selected range should enable the pointer to indicate above 1/2 to 2/3 of the scale scale, so as to reduce the error generated during measurement.
⑤ When the measured frequency is low or the sine wave has large distortion, the error of the clamp ammeter is large.
⑥When the measured current is too small to be displayed on the meter head, the measured wire can be wound back and forth several times in the jaws, and the measured data can be reflected in the measured current value by dividing the measured data by the number of windings in the jaws .
⑦ After the measurement is completed, the clamp ammeter range switch should be placed in the highest measurement range.
(2) Problems that should be paid attention to when using clamp ammeter
①Because the clamp ammeter is in contact with the line under test, it is necessary to check whether the insulation performance of the meter is good before measurement, that is, the shell is not damaged, and the handle is clean and dry.
② When measuring, wear insulating gloves or clean wire gloves.
③ When measuring, pay attention to keep a safe distance between each part of the body and the charged body (the safe distance for low-voltage systems is 0.1/0.3m).
④ Clamp ammeters cannot measure the current of bare conductors.
⑤ It is strictly forbidden to switch the gear of the clamp ammeter during the measurement; if it is necessary to change the gear, the measured wire should be withdrawn from the jaw before changing the gear.
⑥Select the clamp ammeter strictly according to the voltage level. The clamp ammeter of low voltage level can only measure the current in the low voltage system, and cannot measure the current in the high voltage system. It is strictly forbidden to use clamp ammeters for current measurement of circuits above 380V.
