The principle of measuring current with a multimeter
The basic principle of the multimeter is to use a sensitive magnetoelectric DC ammeter (microammeter) as the head.
When a tiny current passes through the meter, there will be a current indication. However, the meter head cannot pass a large current, so some resistors must be connected in parallel or in series on the meter head for shunt or step-down, so as to measure the current, voltage and resistance in the circuit.
In the measurement process of the digital multimeter, the conversion circuit converts the measured value into a DC voltage signal, and then the analog/digital (A/D) converter converts the voltage analog quantity into a digital quantity, and then counts through an electronic counter, and finally uses the digital measurement result. displayed directly on the display.
