1. Analog Multimeter
2. Digital Multimeter 1. Analog Multimeter The digital meters work on the principle of quantization. The analog quantity to be measured is first subdivided or quantized into a number of small intervals up to many decimal places. The objective of the digital instrument is then to determine in which portion of the subdivision the measure and can thus be identified as an integral multiple of the smallest unit called the quantum, chosen for subdivision. The measuring procedure thus reduces to one of the counting the number of quanta present in the measurand. The digital instruments indicate the reading directly in decimal numbers. This is done by using a “digital display device”. 2. Digital Multimeter Basically the digital meters use the “Digital Voltmeter” (DVM). These display the value of a.c or d.c voltages being measured directly as discrete numerals in the decimal number system. If current is to be measured, it is passed through a standard resistor. The voltage appearing across the resistor is then measured with a “DVM”. The value of current can thus be known from the counts appearing on the counters of the readout system of DVM. Similarly a resistance is to be measured, a fixed current is first passed through a resistor. The voltage drop across the resistor, which is proportional to the resistance is measured through DVM. Other physical quantities may also be measured through DVMs by using suitable transducers to feed the input of the DVM.
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