Pasirinkimas skaitmeniniai multimetrai
1. Pagrindinis DC įtampa tikslumas
Įvairūs signalai išmatuoti a skaitmeninis multimetras galiausiai bus konvertuojami į DC įtampą tipus matavimą matavimą per grandinę.
Todėl , the basic DC voltage accuracy of a digital multimeter has become the most important technical indicator for measurement the accuracy of a digital meter. And paprastai , the accuracy of the DC voltage marked on the digital meter should be the annual accuracy.
2. Skaitymas skiriamoji geba
Jis nurodo į the effective reading resolution value that can be displayed on the digital meter screen, or it can simply understood that the number of digits behind the Decimal separator can be displayed on the screen at most when measurement small signals. For example, a six and a half digit multimeter paprastai displays a value of six digits after the Decimal separator when measurement 1V voltage.
3. Matavimas tipas
Į dažniausiai naudojamas matavimas tipai apima AC/DC įtampa, srovė 2c ir varža. srovė skaitmeninis multimetras gali taip pat teikti funkcijos tokie as talpa, dažnis, diodas, laidumas testavimas, bet koks jutiklis matavimas, ir signalas statistika.
4. Signalas matavimas diapazonas
The measurement range of different models of digital multimeter is different, for example, the Agilent 34401A current range is up to 3A. If I want to measure a current of 9A, I need to choose another model of digital multimeter. Please check the numerical range of the oftenly measured data before making a selection.
5. Ryšys sąsaja
Yra keturi pagrindiniai tipai of communication interfaces for digital meters: USB, GPIB, LAN, and RS232. Most used for communication between instruments and computers, facilitating the time transmission, storage, and analysis of measurement data. For example, it is more convenient for us to choose a LAN interface when pplacement instruments far from the computer. Jei the instrument is very close and only needs to provide high-speed data transmission, then USB will be very convenient. If it is conducive to system bus control integration, then GPIB will be labai patogu.
1. Kai pasirinkimas the resistance gear, tiesiogiai matas the voltage, and the multimeter will burn out.
2. Kai the probe is connected to the current test port, measure the voltage of the circuit. Because the internal resistance of the current connection port is very small, it will short-circuit, and the short-circuit will instantly generate a large amount of current flowing through the multimeter, causing the multimeter to burn out.
3. If the probe is connected to the voltage test port to measure the current, the internal resistance of the Voltmeter is extremely large, and the multimeter will be connected in series to the circuit when measuring the current.
Todėl, the multimeter will be divided into the majority of the circuit voltage due to its labai high internal resistance, causeing the power of the wholere circuit power to be added to the internal resistance of the multimeter, causing it to burn out.
