Main technical characteristics of commonly used clamp ammeters
Use of clamp ammeter
①Clamp-type ammeters have a low accuracy level and are often used in situations where measurement requirements are not high.
② Before 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.
③There are usually multiple scales on the dial of the clamp ammeter. When measuring, the scale corresponding to the range set by the range switch should be selected.
④The selected measuring range should enable the pointer to indicate more than 1/2 to 2/3 of the scale scale to reduce errors during measurement.
⑤When 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 small and cannot be displayed on the meter, the measured wire can be wound back and forth in the jaws a few more times. The measured data only needs to be divided by the number of turns in the jaws to reflect the measured current value. .
⑦After the measurement is completed, the range switch of the clamp ammeter should be set to the highest measurement range.
Things to note when using clamp ammeters
① Since the clamp ammeter needs to contact the circuit under test, be sure 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, you should wear insulating gloves or clean wire gloves.
③When measuring, attention should be paid to keeping a safe distance between all parts of the body and charged objects (the safe distance for low-voltage systems is 0.1/0.3m).
④Clamp ammeter cannot measure the current of bare conductors.
⑤ It is strictly forbidden to switch the gear of the clamp ammeter during the measurement process; if it is necessary to change gears, the conductor under test should be withdrawn from the jaws first and then change the gear.
⑥Select the clamp ammeter strictly according to the voltage level. Low-voltage clamp ammeters can only measure the current in low-voltage systems, but cannot measure the current in high-voltage systems. It is strictly prohibited to use the clamp ammeter for current measurement in circuits above 380V.
