How to judge the quality of resistance level (OHM Ω)?
Note, please do not use resistance gear to measure voltage. When measuring online, the equipment should be powered off, and lines with capacitors or batteries should be fully discharged before measurement can be made. This is easier to detect. Generally, those who engage in electronic maintenance will have some resistive components on hand, so they can just measure the resistance directly.
How to judge (test) whether the AC voltage range (ACV) of the multimeter is good?
Household testing sources include AC adapters and household sockets (two-phase 220V kind, it is best not to measure the three-phase 380V kind, because this voltage is more dangerous and harmful to the instrument (at least a multimeter with CAT III 600V or above) and the user (all have higher requirements). For safety reasons, it is recommended to measure a relatively small voltage first, such as an AC adapter, and then measure the voltage of a household socket. For specific safe operation methods, please refer to the product manual.
How to judge (detect) whether the DC voltage range (DCV) of the multimeter is good?
When testing, you must first find the testing source. Since we are doing qualitative and quantitative measurements, there are many testing sources available. 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, etc. When testing, set the multimeter to the required DC voltage range, insert the test leads according to the instructions, connect the detection source, and read the reading on the LCD. As long as the measured value is around the nominal voltage, it will be fine. .
PS: Let me repeat again, we are doing qualitative and quantitative measurements, so we can use these sources, because the voltage of these sources is not very stable. For example, a 1.5V battery, a new battery may reach more than 1.6V, and an old battery may only have A few tenths of a volt.
