What are the differences between pointer multimeters and digital multimeters
Multimeters, also known as multimeters, triple meters, or multiplexers, are divided into pointer type multimeters and digital multimeters. It is a multifunctional and multi range measuring instrument. Generally, a multimeter can measure DC current, DC voltage, AC current, AC voltage, resistance, and audio level. Some can also measure AC current, capacitance, inductance, and some parameters of semiconductors.
A pointer multimeter is an average type instrument that has intuitive and visual reading indications. (Generally, reading numerical values is closely related to the angle of pointer swing, so it is very intuitive).
A digital multimeter is an instantaneous style instrument. It uses a sample taken every 0.3 seconds to display the measurement results. Sometimes, each sampling result is only very similar and not exactly the same, which is not as convenient for reading the results as a pointer type.
A pointer type multimeter generally does not have an amplifier inside, so its internal resistance is small. For example, the MF-10 model has a DC voltage sensitivity of 100 kiloohms/volt. The DC voltage sensitivity of the MF-500 model is 20 kiloohms/volt.
Due to the use of an operational amplifier circuit internally, the internal resistance of a digital multimeter can be large, often at 1M ohms or higher. (i.e. higher sensitivity can be achieved). This allows for less impact on the tested circuit and higher measurement accuracy.
The pointer type multimeter, due to its small internal resistance and the use of discrete components to form a shunt and voltage divider circuit. So the frequency characteristics are uneven (compared to digital ones), while the frequency characteristics of pointer type multimeters are relatively better. The internal structure of the pointer type multimeter is simple, so it has lower cost, fewer functions, simple maintenance, and strong overcurrent and overvoltage capabilities.
The digital multimeter uses various oscillation, amplification, and frequency division protection circuits internally, so it has many functions. For example, it can measure temperature, frequency (within a lower range), capacitance, inductance, and be used as a signal generator.
Due to the use of integrated circuits in the internal structure, digital multimeters have poor overload capacity (although some can now automatically shift gears, protect themselves, etc., but their use is more complex), and they are generally not easy to repair after damage.
The output voltage of the pointer type multimeter is relatively high, such as 10.5 volts, 12 volts, etc. The current is also large (such as MF-500 * 1 ohm, with a maximum of around 100 milliamperes), making it convenient to test thyristors, light-emitting diodes, and other components.
The output voltage of a digital multimeter is relatively low (usually not exceeding 1 volt). It is inconvenient to test some components with special voltage characteristics, such as thyristors, light-emitting diodes, etc.
