Several forms of digital multimeter classification
Digital multimeters can be classified into laboratory type, universal type, and panel type according to their usage locations. Laboratory instruments have high accuracy and strict usage conditions, and are generally used for standard or precision measurements. Universal instruments are used for general measurements. The panel type instrument has a simple structure and low accuracy, and is often installed on the panel as an indicator meter. Therefore, this type of instrument is also known as a digital panel meter, abbreviated as DPM (Digital Panel Meter). Digital voltmeters can also be classified into desktop, portable, and handheld types according to their usage. In addition, it can also be classified in the following forms:
- Classified by range conversion method:
1. Manual range
This type of instrument has a lower price, but the operation is more complex. If the range is not selected appropriately, it is easy to overload the instrument.
2. Automatic range
Automatic range digital multimeter can greatly simplify operation, effectively avoid overload, and keep the instrument in the optimal range, thereby improving measurement accuracy and resolution. The price of such instruments is relatively high.
2, Classified by function:
1. A simple multimeter has a low price and poor performance indicators. It is mainly used to measure voltage, current, and resistance.
2. The multifunctional multimeter has strong measurement function and a high selling price. The added functions mainly include measuring capacitance, inductance, transistor parameters (such as hFE, ICEO, ICBO, etc.), low resistance resistors (D Ω range), voltage of the battery with rated load, and high voltage. Some multimeters can also check the illumination of light-emitting diodes (LEDs).
3. Intelligent multimeter
4. Dual display and multi display digital multimeters such as the American Fluke dual display multimeter.
5. Specialized instruments
3, Classified by purpose:
1. Low end digital multimeter
It belongs to the popular 3 and 1/2 position instrument, with simple functions and a price comparable to a pointer multimeter. Typical products include DT810, DT830C, DT830DM, etc.
2. Mid range digital multimeter
(1) Multi functional digital multimeter. This type of instrument is generally equipped with capacitor mode, temperature measurement mode, frequency mode, and some also add high blocking and conductivity modes. Typical products include DT890C and DT890C+type 3 and 1/2 digit digital multimeter.
(2) 4 and 1/2 digit digital multimeter, with high accuracy and functional rubber ring, suitable for laboratory measurement.
(3) The voice digital multimeter contains a voice synthesis circuit, which allows colleagues who display numbers to also use voice to report measurement results.
3. Only digital multimeters are available
(1) Mid range intelligent digital multimeter
This type of instrument generally uses a 4-bit microcontroller with an RS232 interface.
(2) Advanced intelligent digital multimeter
It contains 8-16 bit microcontrollers and has multiple functions such as data processing, automatic calibration, and fault self checking.
