How to judge (test) whether the DC voltage range (DCV) of the multimeter is good?
When testing, the first step is to find the testing source. As we are qualitative with a little quantitative measurement, there are many available testing sources. Household testing sources include 1.5V alkaline/carbon batteries (No. 1, No. 5/AA, No. 7/AAA), 1.2V rechargeable batteries, mobile phone chargers, power adapters, and so on. When testing, turn the multimeter to the desired DC voltage range, insert the probes according to the instructions, connect the testing source, and read the reading on the LCD. As long as the measured value is around the nominal voltage, it is sufficient.
How to determine (test) whether the AC voltage range (ACV) of a multimeter is good?
The detection sources for household use include AC adapters and household sockets (for two-phase 220V, it is best not to measure three-phase 380V, as this voltage is more dangerous and requires higher requirements for instruments (at least CAT III 600V multimeter) and users). For safety reasons, it is recommended to measure relatively small voltages, such as AC adapters, before measuring the voltage of household sockets. For specific safety operation methods, please refer to the product manual.
How to determine the quality of DC current range (DCA)?
If there is a known current source, input it directly in the current mode. If not, it's okay. Just input the voltage in the current mode. If it goes out to 1, shift it to the lower range mode until a valid value appears. Please also pay attention to the following points:
A. Please do not input too high voltage to avoid damaging the instrument due to excessive current. Common sources that can be input include regular batteries such as No.5, No.7, etc;
B. When measuring the current of the input voltage, due to the small resistance (load) of the internal resistance of the instrument, if the input is too long, it will damage the source. Therefore, a single input should not exceed 5 seconds as much as possible;
C. The relationship between different high and low ranges, adjacent ranges, is generally 10 times.
