Selection principles of digital multimeter
When choosing a digital multimeter, you must consider the actual needs clearly. For most users, you should mainly pay attention to the matching degree between the performance index of the digital multimeter and the actual use, and choose a cost-effective digital multimeter according to the corresponding performance index. Try to avoid blindly pursuing high performance. A waste of resources due to performance.
For most ordinary users and multimeter enthusiasts, ordinary popular digital multimeters can meet the actual needs well. Popular digital multimeters can measure DCA, AcA, DCV, ACV, Q, VF, HFE and line disconnection. And this kind of digital multimeter is small in size, easy to carry, and the price is relatively cheap, generally around tens of yuan.
When choosing a digital multimeter, first check the appearance of the digital multimeter, carefully check whether the casing of the digital multimeter has cracks, deformation, etc., and whether the LCD screen is scratched, loose, cracked, etc. At the same time, you should also check whether the sockets and jacks on the digital multimeter are loose, and whether there are foreign objects filling the holes. After turning on the power, observe whether there are pen segments left on the LCD, whether the decimal point is displayed normally, and whether the unit symbol is displayed normally. At the same time, when choosing a digital multimeter, you should also pay attention to whether the safety protection device of the digital multimeter is complete, and check whether it has an overcurrent protection device (fast fuse, fuse resistor, self-recovery fuse, current limiting resistor, etc.), overvoltage protection device (two-wire limiting diode, spark arrestor, transient voltage suppressor, etc.), resistance gear protection device (PTC, etc.).
