Comparison of the advantages and disadvantages of ordinary multimeters and digital multimeters:
Both analog and digital multimeters have advantages and disadvantages.
The pointer multimeter is an average meter, which has an intuitive and vivid reading indication. (The general reading value is closely related to the swing angle of the pointer, so it is very intuitive).
A digital multimeter is an instantaneous meter. It takes a sample every 0.3 seconds to display the measurement results, and sometimes the results of each sampling are very similar, not exactly the same, which is not as convenient as the pointer type for reading the results. The pointer multimeter generally does not have an amplifier inside, so the internal resistance is small.
Due to the internal use of the operational amplifier circuit in the digital multimeter, the internal resistance can be made very large, often 1M ohms or greater. (ie higher sensitivity can be obtained). This makes the impact on the circuit under test can be smaller, and the measurement accuracy is higher.
Due to the small internal resistance of the pointer multimeter, discrete components are often used to form a shunt and voltage divider circuit. Therefore, the frequency characteristics are uneven (compared to the digital type), and the frequency characteristics of the digital multimeter are relatively better.
The internal structure of the pointer multimeter is simple, so the cost is lower, the function is less, the maintenance is simple, and the overcurrent and overvoltage ability is strong.
The digital multimeter uses a variety of oscillation, amplification, frequency division protection and other circuits inside, so it has many functions. For example, you can measure temperature, frequency (in a lower range), capacitance, inductance, make a signal generator, and so on.
Since the internal structure of the digital multimeter uses integrated circuits, the overload capacity is poor, and it is generally not easy to repair after damage. DMMs have low output voltages (usually no more than 1 volt). It is inconvenient to test some components with special voltage characteristics (such as thyristors, light-emitting diodes, etc.). The pointer multimeter has a higher output voltage. The current is also large, and it is convenient to test thyristors, light-emitting diodes, etc.
A pointer multimeter should be used for beginners, and two meters should be used for non-beginners.
