1. According to the range conversion method
(1) Manual range
The price of this kind of instrument is low, but the operation is more complicated, and it is easy to overload the instrument due to the inappropriate selection of the range.
(2) Automatic range
The automatic range program digital multimeter can greatly simplify the operation, can effectively avoid overload, and make the instrument in the best range, thereby improving the measurement accuracy and resolution. Relatively speaking, the price of such instruments is relatively high.
2. According to the purpose and function
(1) Low-grade digital multimeter It is a three-and-a-half popular instrument with relatively simple functions and the price is comparable to that of a pointer multimeter.
(2) Mid-range digital multimeter
①Multi-function digital multimeter: This kind of meter is generally equipped with capacitance block, temperature measurement block, frequency ning block, and some also add factory high resistance block, conductance block and inductance block.
② Four-and-a-half-digit multimeter: It has high accuracy and complete functions, and is suitable for laboratory measurement.
③Voice digital multimeter: It contains a speech synthesis circuit, which can broadcast the measurement results by voice while displaying the numbers.
(3) Intelligent digital multimeter
①Mid-range intelligent digital multimeter: This kind of meter generally adopts 4-bit to 8-bit single-chip microcomputer with RS-232 interface.
②High-end intelligent digital multimeter: contains 8-bit to 16-bit single-chip microcomputer, with data processing, automatic calibration, fault self-checking and other functions.
(4) Dual display and multi-display digital multimeter
The characteristic of the dual-display instrument is that an analog bar graph display is added on the basis of the digital display, which can quickly reflect the change process and trend of the measured change. The multi-display instrument is developed on the basis of the dual-display instrument. Can display more than two groups of data at the same time (such as maximum value, minimum value).
(5) Special digital instrument
For example ODM5514, desktop multimeter
(6) Digital calibrator
This instrument has high accuracy and resolution, and can automatically calibrate temperature, voltage and current changes
