Hold Adaptor for Voltmeters

Modern, good-quality multimeters have a hold function that enables a measurand to be read even after the test prods have been removed. The present adaptor is intended to add this facility to multimeters and voltmeters that are not so equipped.In meters with a hold function, the measurand is quantized by an analogue-to-digital converter (ADC) and held in memory. This type of hold function is fairly sophisticated, but for can be attained by a rather less expensive and simpler analogue circuit.