Basic instruments: Multimeters

Multimeters have more than 100 years of history and they have changed a lot over time, from the analog-based instruments to the modern digital ones. Electronic and digital techniques have allowed the development of very high accuracy digital multimeters (DMM) with accuracies in the order of 1 part in 106. The core of DMMs is the analog to digital converter (ADC). Generally, DMMs have a set of menus that allows to adjust many parameters, such as offset, resolution, sampling rate, accuracy, and communication settings, among others. For all type of multimeters, it is necessary to take into account the loading effect that the instrument has on the device under test. Safety is an important characteristic of any type of instrument, but in the case of multimeters this is more relevant because these instruments are intended to be used in a wide range of installations.