Advantages and disadvantages of digital multimeter and pointer multimeter
Multimeters, divided into digital multimeters and pointer multimeters, are indispensable measuring instruments in power electronics and other departments. Generally, the main purpose is to measure voltage, current and resistance. It is a multi-functional and multi-range measuring instrument. Whether it is digital or traditional, they all play an important role in measurement, but what are the advantages and disadvantages of the two in comparison?
Pointer multimeter:
1. The pointer multimeter is an average meter, which has an intuitive and vivid reading indication.
2. Generally, the pointer multimeter does not have an amplifier inside, so the internal resistance is relatively small.
3. Due to the small internal resistance of the pointer multimeter and the use of discrete components to form a shunt and voltage divider circuit, the frequency characteristics are uneven.
4. The internal structure of the pointer multimeter is simple, so the cost is lower, the functions are less, the maintenance is simple, and the overcurrent and overvoltage capabilities are strong.
5. The output voltage of the pointer multimeter is relatively high, and the current is also large, which can conveniently test thyristors and light-emitting diodes.
Digital multimeter:
1. The digital multimeter is an instantaneous sampling instrument. It takes a sample every 0.3 seconds to display the measurement results. It is not as convenient to read the results as the pointer type.
2. Since the digital multimeter uses an operational amplifier circuit inside, the internal resistance can be made very large, which makes the impact on the circuit under test smaller and the measurement accuracy is higher.
3. The digital multimeter uses a variety of oscillation amplification, frequency division, protection and other circuits inside, so it has many functions.
4. Since the internal structure of the digital multimeter mostly uses integrated circuits, the overload capacity is relatively poor, and it is generally not easy to repair after damage.
5. The output voltage of the digital multimeter is low (usually not more than 1 volt), and it is inconvenient to test some components with special voltage characteristics, such as thyristors and light-emitting diodes.
