Advantages and disadvantages of conventional multimeters and digital multimeters
A pointer multimeter is an averaging instrument. It has an intuitive. Visual indication of the reading.
(General readings are closely related to the angle of swing of the pointer, so it is very intuitive).
Digital multimeter is an instantaneous style instrument. It uses 0.3 seconds to take a sample to display the measurement results. Sometimes the results of each sample are only very similar. Not exactly the same. This is not as convenient for reading results as the pointer type.
Pointer multimeters generally do not have an internal amplifier. So the internal resistance is small. The MF-10, for example, has a DC voltage sensitivity of 100 kOhm/volt. The MF-500 has a DC voltage sensitivity of 20 kOhm/volt.
Digital multimeters have an internal op amp circuit. Internal resistance can be made very large. Often in 1M ohms or greater. (i.e., can get a higher sensitivity). This makes the impact on the measured circuit can be smaller. Higher measurement accuracy.
Pointer multimeter due to the small internal resistance, and more discrete components to form a shunt voltage circuit. So the frequency characteristics are not uniform (relative to digital). And the frequency characteristics of the pointer multimeter is relatively good.
Pointer multimeter internal structure is simple so the cost is low. Fewer functions. Simple maintenance. Stronger overcurrent and overvoltage capability.
Digital multimeter adopts many kinds of oscillation, amplification. Frequency division. Protection circuitry so more functions, such as temperature measurement. Frequency (in a lower range). Capacitance, inductance. Or as a signal generator and so on.
Due to the internal structure of many integrated circuits, so the overload capacity is poor. (But now some have been able to automatically shift gears. Automatic protection. But the use of more complex). Damage is generally not easy to repair.
Digital multimeter output voltage is low (usually no more than 1 volt). For some special voltage characteristics of the components of the test inconvenience (such as, silicon controlled, light-emitting diodes, etc.).
Pointer multimeter output voltage is higher, (10.5 volts, 12 volts, etc.).
Current is also large (such as MF-500 * 1 ohm gear maximum of 100 mA or so) can be convenient to test the SCR, light-emitting diodes and so on.
