Repair for a Multimeter Needle That Fails to Return to Zero
After using a multimeter for a period of time, it was found that the pointer could not reset to zero, and sometimes the pointer would stay at a certain deviation position without moving. The reason for this is that the case of the multimeter is made of organic glass. Due to the frequent use of hands or other velvet cloth to wipe the dust on the surface during use, with the increase of friction times over time, static electricity is generated inside the case, especially in dry air conditions during autumn and winter. Therefore, the pointer will stay in a certain position during measurement.
When encountering the malfunction of electrostatic adsorption pointer, you can dilute 5% new Jie'er Mie solution (available in chemical stores) with 30% distilled water, then dip a cotton ball in the prepared solution and evenly apply a layer inside and outside the universal case. Let it dry at a temperature of about 38-40 ° C to eliminate the fault.
The static electricity on the dial can also be eliminated by adding glycerin and saline solution.
Instructions and precautions for using a multimeter
Check and prepare: Before use, check whether the appearance of the multimeter is intact and whether the knobs and switches are flexible and reliable. Ensure that the pointer is at zero position or mechanically zeroed (i.e. place the multimeter pointer at zero voltage or zero current position).
Select range: Choose the appropriate range based on the size of the measured physical quantity. If a range that is too small is chosen, the reading will be inaccurate, and if a range that is too large is chosen, it will waste battery energy.
Measure voltage:
Insert the red probe into the "V/Ω" socket and the black probe into the "COM" socket.
Turn the range switch to the corresponding voltage measurement gear and select AC or DC measurement.
Connect the test probes in parallel in the circuit under test and maintain stability before reading.
Measure current:
Set the range switch to the current measurement mode and select AC or DC measurement.
Connect the test probe in series in the circuit under test and maintain stability before reading.
