Advantages and disadvantages of ordinary multimeter and digital multimeter

Advantages and disadvantages of ordinary multimeter and digital multimeter

Both analog and digital multimeters have their own advantages and disadvantages.

Pointer multimeter is an average value meter. It has an intuitive and vivid reading indication.

(Generally, the reading value is closely related to the pointer swing angle, so it is very intuitive).

A digital multimeter is an instantaneous sampling instrument. It takes a sample every 0.3 seconds to display the measurement result. Sometimes the results of each sampling are only very close, but not exactly the same. This is not as convenient as the pointer type for reading the results.

Pointer multimeters generally do not have internal amplifiers, so the internal resistance is small. For example, the DC voltage sensitivity of the MF-10 model is 100 kilo-ohms/volt, which is considered good. The DC voltage sensitivity of the MF-500 model is 20 kilo-ohms/volt.

Since digital multimeters use operational amplifier circuits internally, the internal resistance can be very large, often 1M ohm or greater (i.e., higher sensitivity can be achieved). This reduces the impact on the measured circuit and provides higher measurement accuracy.

The pointer type multimeter has a small internal resistance and mostly uses discrete components to form a shunt and voltage divider circuit. Therefore, the frequency characteristics are uneven (relative to digital). The frequency characteristics of the pointer type multimeter are relatively better.

Pointer multimeter has a simple internal structure, so the cost is low, the functions are few, the maintenance is simple, and the over-current and over-voltage capabilities are strong.

Digital multimeters have many functions because they use a variety of oscillation, amplification, frequency division, protection and other circuits. For example, they can measure temperature, frequency (in a lower range), capacitance, inductance, or act as a signal generator, etc.

Since the internal structure mostly uses integrated circuits, the overload capacity is poor. (However, some of them can now automatically shift gears and automatically protect, but they are more complicated to use.) It is generally not easy to repair after damage.

The output voltage of a digital multimeter is low (usually no more than 1 volt). It is inconvenient to test some components with special voltage characteristics (such as thyristors, light-emitting diodes, etc.)

Pointer multimeters have higher output voltages (10.5 volts, 12 volts, etc.).

The current is also large (for example, the maximum current of MF-500*1 ohm is about 100 mA), which can be used to conveniently test thyristors, light-emitting diodes, etc.

For beginners, a pointer multimeter should be used.

For non-beginners, two instruments should be used.