Digital multimeters:

Digital multimeters offer a number of significant advantages when compared with their more humble analogue counterparts.  The display fitted to a digital multimeter usually consists of a 3½ digit seven-segment display - the '½' simply indicates that the first digit is either blank (zero) or 1.  Consequently, the maximum indication on the 2V range will be 1.999V and this shows that the instrument is capable of offering a resolution of 1mV on the 2V range.  The resolution obtained from a comparable analogue meter would be of the order of 50mV, or so, and thus the digital instrument provides a resolution which is many times greater than its analogue counterpart.

The controls and display provided by a simple digital multimeter are shown in the diagram below.  The mode switch and range selector allows you to select from a total of twenty ranges and eight measurement functions.  These functions are:

DC voltage (DC, V)                                DC current (DC, A)

AC voltage (AC, V)                                AC current (AC, A)

Resistance (OHM)                                 Capacitance (CAP)

Continuity test (buzzer)                        Transistor current gain (h_FE)