Principles of Multimeter Design
The digital multimeter's measurement process begins by converting the measured value into a DC voltage signal using a conversion circuit, followed by analog/digital (A/D) conversion of the voltage analog quantity into a digital quantity, counting with an electronic counter, and using the digital measurement result that is directly displayed on the display.
The conversion circuit section of the multimeter performs the function of measuring voltage, current, and resistance. The measurement of current and resistance is dependent on the measurement of voltage, meaning that the digital multimeter is built on the foundation of the digital DC voltmeter.
The analog to digital converter of the digital DC voltmeter transforms the continuously changing analog voltage amount into a digital quantity, which is then tallied by the electronic counter to produce the measurement result and displayed by the decoder display circuit. Under the influence of the clock, the logic control circuit directs the coordinated operation of the circuit and completes the full measurement procedure in sequence.
