Buying points for digital multimeters
When buying a multimeter, first observe the case to see if it is smooth and shiny, without scratches or cracks, and the scale on the dial is clear and clean without stains.
Then, rotate the down-converter switch to see if it is light and flexible, free from jamming and noise. You can also shake the multimeter horizontally a few times, the pointer should have good damping, the swing should not be too large, and there is no impact sound in the meter.
Check the mechanical zero adjustment (the corrector is in the middle of the surface) to see if the pointer can cross zero and whether it can be accurately adjusted to the zero point.
Finally, check the ohm gear of the battery on the watch: short-circuit the two test pens, turn the zero-setting potentiometer forward and reverse, the pointer should swing back and forth at "0" Ω, and can be accurately adjusted to the zero position.
In addition, you can also check according to the product performance in the manual to see if it meets the specified technical requirements.
