Introduction to the Advantages and Disadvantages of Digital Multimeters and Pointer Multimeters
Multimeters, divided into digital multimeter and pointer multimeter, are indispensable measuring instruments in power electronics and other departments. They are generally used to measure voltage, current, and resistance, and are a multifunctional and multi range measuring instrument. Both digital and traditional methods play an important role in measurement, but what are their advantages and disadvantages compared to each other?
Pointer multimeter
1. A pointer multimeter is an average type instrument with intuitive and visual reading indications.
2. A pointer multimeter generally does not have an amplifier internally, so the internal resistance is small.
3. The frequency characteristics of a pointer type multimeter are uneven due to its small internal resistance and the use of discrete components to form a shunt and voltage divider circuit.
4. 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.
5. The pointer type multimeter has a high output voltage and current, making it easy to test thyristor, LED, etc.
Digital multimeter:
1. A digital multimeter is an instantaneous sampling instrument that uses a sample taken every 0.3 seconds to display measurement results, which is not as convenient as a pointer type for reading results.
2. Due to the internal use of an operational amplifier circuit, the digital multimeter can have a large internal resistance, which can have a smaller impact on the tested circuit and higher measurement accuracy.
3. The digital multimeter uses various internal oscillation amplification, frequency division, protection circuits, etc., so it has many functions.
4. Due to the use of integrated circuits in the internal structure of a digital multimeter, its overload capacity is poor and it is generally not easy to repair after damage.
5. The output voltage of a digital multimeter is relatively low (usually not exceeding 1 volt), making it inconvenient to test some components with special voltage characteristics, such as thyristors, light-emitting diodes, etc.
