The difference between an analogue multimeter and a digital multimeter
The analog multimeter is an average meter with an intuitive and vivid reading indication. The digital multimeter is an instantaneous sampling instrument. It uses 0.3 seconds to sample and the results are only very similar, not exactly the same, and it is not very convenient to read the results.
Analog multimeters generally do not have an amplifier inside, so the internal resistance is small. For example, the MF-10 model has a DC voltage sensitivity of 100 kΩ/V. This is considered the best. The DC voltage sensitivity of the MF-500 model is 20 kΩ/V. Because the digital multimeter uses an operational amplifier circuit inside, the internal resistance can be made very large. It is often 1M ohm or larger, which makes the impact on the circuit under test smaller and the measurement accuracy higher.
Because the internal resistance of the pointer multimeter is small, discrete components are often used to form a shunt and voltage divider circuit. Therefore, the frequency characteristics are uneven (compared to digital ones), while the frequency characteristics of analog multimeters are relatively better.
The internal structure of the analog multimeter is simple, so it has lower cost, fewer functions, simple maintenance, and strong overcurrent and overvoltage capabilities. The digital multimeter uses a variety of oscillation, amplification, frequency division, protection and other circuits internally, so it has many functions, such as measuring temperature. frequency (in a lower range), capacitance, inductance, or signal generator etc. Since the internal structure mostly uses integrated circuits, the overload capability is poor, and it is generally difficult to repair after damage.
The output voltage of the pointer multimeter is high and the current is also large (for example, the MF-500*1 ohm range has a maximum of about 100 mA), which can easily test thyristors, light-emitting diodes, etc. A digital multimeter, on the other hand, has a lower output voltage (usually no more than 1 volt). It is inconvenient to test some components with special voltage characteristics (such as thyristors, light-emitting diodes, etc.).
