A multimeter is a magnetoelectric instrument with a rectifier that can measure various electrical parameters such as AC and DC current, voltage, and resistance. Some can also measure the main parameters of transistors and the capacitance of capacitors. Fully mastering the use of multimeters is one of the most basic skills of multimeter maintenance personnel. This article will share with you the use and precautions of the multimeter in the maintenance work.
Precautions:
1. If the magnitude of the voltage or current to be measured cannot be estimated in advance, it should be dialed to the highest range to measure once, and then slowly reduce the range to an appropriate position as the case may be. After the measurement is completed, turn the range switch to the highest voltage block and turn off the power.
2. When the scale is full, the meter only displays the number "1" in the highest digit, and the other digits disappear. At this time, a higher range should be selected.
3. When measuring voltage, the digital multimeter should be connected in parallel with the circuit under test. When measuring the current, it should be connected in series with the circuit under test, and it is not necessary to consider the positive and negative polarities when measuring the direct current.
4. The editor of the Fluke Multimeter Repair Center reminds everyone that when the AC voltage block is misused to measure the DC voltage, or the DC voltage block is misused to measure the alternating current, the display will display "000", or the number on the low position will jump.
5. It is forbidden to change the range when measuring high voltage (above 220V) or high current (above 0.5A) to prevent arcing and burning of switch contacts.
When using a Fluke multimeter, pay attention to checking the cable for moisture. When repairing the line of the Fluke multimeter, if the input level of the amplifier is lower than the level loss value of the specified cable length, the resistance of the cable can be measured by the pointer type multimeter (R×1 or R×100 block). If the needle is charged like a capacitor It seems to rise slowly, which indicates that the cable is seriously damp or there is more water in the cable.
And also pay attention to distinguish the phase line and neutral line of the multimeter:
1. Pointer multimeter to distinguish phase line and zero line
2. Digital multimeter to identify phase line and zero line
When using a multimeter to repair the problem of the electric drive control circuit, pay attention to:
1. Use the resistance measurement method to repair the problem of the electric drive control circuit
2. Use the voltage measurement method to repair the problem of the electric drive control circuit
The above is the maintenance precautions for Fluke multimeter
