What should you pay attention to when using a clamp ammeter?
1. In order to prevent insulation breakdown and personal electric shock, the voltage of the line being measured shall not exceed the rated voltage of the clamp ammeter, let alone the current of high-voltage lines.
2. Before measuring, check whether the meter pointer is at zero position. If it is not at zero position, it should be adjusted to zero position. At the same time, a rough estimate of the measured current should be made and an appropriate range should be selected. If the measured current cannot be estimated, the clamp-type ammeter should be placed in the highest gear first and then gradually lowered until the pointer is in the middle of the scale.
3. Pay attention to the voltage level of the clamp ammeter. Do not use low-voltage meters to measure the current of high-voltage circuits to avoid accidents.
4. When measuring, the wire under test should be placed in the center of the jaws. The two surfaces of the jaws should be well connected. If vibration or collision sound is found, turn the instrument wrench a few times or open and close it again. If there is dirt on the jaws, you can use gasoline to clean them.
5. After measuring a large current, if you measure a small current immediately, you should open and close the jaws several times to eliminate the residual magnetism in the core.
6. Do not switch the measuring range during the measurement process to avoid causing the secondary circuit to instantly open, inducing high voltage and breakdown of the insulation. When it is necessary to change the measuring range, the jaws should be opened first.
7. When measuring in places where it is difficult to read current readings, you can first lock the pointer with the brake, and then go to a convenient place to read the value.
8. If the conductor under test is a bare conductor, adjacent phases must be isolated with insulating plates in advance to avoid phase-to-phase short circuit when the jaws are opened.
9. When measuring a current less than 5A, in order to obtain an accurate reading, you can wind the wire a few more times and put it into the clamp for measurement. However, the actual current value is the reading divided by the number of wires put into the clamp.
10. When measuring, if there are other current-carrying conductors nearby, the measured value will be affected by the current-carrying conductor and cause errors. At this time, the jaws should be placed on the side away from other conductors.
11. After each measurement, the switch for adjusting the current range should be placed in the highest gear to avoid damage to the instrument due to measurement without selecting the range the next time it is used.
12. For clamp meters with voltage measurement blocks, current and voltage must be measured separately and not measured at the same time.
13. Wear insulating gloves and stand on an insulating mat when measuring. Pay attention to safety when taking readings and do not touch other live parts.
14. When using a clamp ammeter, try to stay away from strong magnetic fields to reduce the impact of the magnetic field on the clamp ammeter. When measuring a smaller current, if the clamp ammeter has a larger range, the wire to be measured can be wound around the mouth of the clamp ammeter several times. The actual current value in the line should be the meter reading divided by the number of turns of the wire on the clamp ammeter. number.
