Clamp ammeter voltage measurement techniques
1. The voltage of the line being tested must not exceed the rated voltage of the clamp ammeter, let alone the current of the high-voltage line, in order to prevent insulation breakage and human electric shock.
2. Verify that the meter's pointer is at zero before taking a measurement. It should be set to zero if it is not already. The measured current should also be generally calculated at this time, and a suitable range should be chosen. Put the clamp ammeter in the highest gear first, then slowly lower the switch until the pointer is in the center of the scale if an estimate of the observed current cannot be made.
3. To prevent mishaps, it is important to pay attention to the clamp ammeter's voltage level and to avoid measuring the high voltage circuit's current with a low voltage meter.
4. The measured wire should be positioned in the jaw's middle during measuring. The jaws' two surfaces ought to be closely related. The instrument wrench should be moved a few times or opened and closed again if vibration or impact sounds are heard. Gasoline can be used to clean the jaws' dirtiness.
5. If you measure a tiny current right away after measuring a large current, you should repeatedly open and close the jaws to remove any remaining magnetism in the iron core.
6. Avoid changing the range while taking the measurement so that you don't suddenly produce high voltage, open the secondary circuit, and damage the insulation. The jaws should always be opened first when the range needs to be adjusted.
7. When taking measurements in an area where it is challenging to see the current reading, you can first lock the pointer with the brake before reading the value in a comfortable location.
8. To prevent a phase-to-phase short circuit when the jaws are opened, the neighboring phases of a bare wire that will be examined must be insulated by insulating plates beforehand.
9. When measuring a current less than 5A, the wire can be twisted multiple times and placed in the jaw for measurement. The actual current value is calculated by dividing the reading by the number of wires placed in the mouth.
10. If there are any other current-carrying wires close by when you are measuring, they will alter the results and introduce inaccuracies. The jaw should now be positioned to the side that is distant from other conductors.
11. To prevent damage to the instrument from subsequent measurements without selecting the range, the switching switch for modifying the current range should be set to the highest gear after each measurement.
12. The current and voltage should not be measured simultaneously when using a clamp meter that has a voltage measurement gear.
13. When measuring, put on insulating gloves and stand on an insulating mat. Whilst reading, be mindful of your surroundings and avoid touching any live components.
14. To lessen the impact of magnetic fields on the clamp ammeter, try to avoid strong magnetic fields when using the clamp ammeter. The test wire can be coiled numerous times around the clamp ammeter's mouth to measure small currents if the clamp ammeter's range is wide. The clamp ammeter measurement should be divided by the number of turns of wire coiled on it to determine the actual current value in the line.
