The digital multimeter, DMM, is one of the most common items of test equipment used in the electronics industry today. While there are many other items of test equipment that are available, the multimeter is able to provide excellent readings of the basic measurements of amps, volts and ohms. In addition to this the fact that these digital multimeters use digital and logic technology, means that the use of integrated circuits rather than analogue techniques, enables many new test features to be embedded in the design.