What Common Functions Does a Digital Multimeter Generally Have?
There are many models and types of digital multimeters, and the measurement items and functions of different models and types of digital multimeters also vary. For example, some digital multimeters use one switch to select measurement items and measurement ranges, while others use two switches to select measurement items and measurement ranges separately (the measurement item switches are often button type).
Generally, symbols for each measurement item are marked on the dial: DCV (DC voltage) mode, ACV (AC voltage) mode, DCA (DC current) mode, ACA AC current mode, Ω or OHM or Oh mode, H Ω high blocking, L Ω ground blocking, LO Ω, LOW Ω or OHM LOV low-power method electrical blocking, ns conductivity mode, buzzer mode, diode mode, capacitor mode, frequency mode, temperature mode, etc.
Digital multimeters generally have these functions:
Firstly, the digital multimeter has the function of automatic zero adjustment, but except for the capacitor mode, this can ensure that the output of the multimeter is also zero when there is zero input;
Secondly, it can automatically switch and display polarity, that is, when the polarity of the measured voltage or current is inconsistent with the polarity of the probe, the instrument can automatically display a negative sign, while the pointer multimeter needs to exchange the probe. For non automatic range switching digital multimeters, they can automatically display overload when overloaded (usually displaying "1" or "-1", the negative sign depends on the polarity of the instrument input);
Thirdly, when the battery voltage is too low and causes insufficient power supply, the instrument can automatically prompt by displaying specific symbols (such as "LOBATT", "-", etc.). In addition, some digital multimeters can automatically display the measured units and symbols (such as "mA", "K Ω", etc.). The digital display of a digital multimeter enables faster and more accurate readings of measurement results, thereby avoiding human reading errors and reducing visual fatigue for users. The advantages of a digital multimeter are also reflected in its compact size and lightweight quality. Due to the use of large-scale integrated circuits and low-power circuit components inside the instrument, the weight of the instrument generally does not exceed 300g. Its compact size allows it to be almost packed into a pocket, which brings great convenience to personnel who frequently go out for maintenance services.
