A novel measurement technique for DC voltage and current reducing the DMM loading effects

Abstract

A novel technique for the measurement of DC voltage and current that reduces the loading effects of a digital multimeter is presented in this work. When the variable of interest is a current (voltage), instead of connecting an ammeter (voltmeter) in series (parallel), it is proposed to connect a voltmeter (ammeter) and an ohmmeter in series (parallel) at the same two terminals conventionally employed. The application of this new measurement technique reduces the loading effects by a factor of at least 100 but up to 500, in comparison with those obtained in the conventional method.

Loading-Effects Reduction Using a Voltmeter in Series and an Ammeter in Parallel

“…The proposed approach puts into practice the statements formulated in [10], which were originally thought to analyze linear circuits but are also useful to improve the accuracy of DC measurements under certain conditions. Very preliminary experimental results applying such a novel approach were reported in [11], although the resulting values of error were, in the critical scenarios, between 50 and 100 times higher and, hence, it was not possible to prove there the theoretical model.…”

Nodal and Mesh Analysis Simplification by Introducing a Theorem-Based Preliminary Step

“…With the background of the Thévenin and Norton theorems, a novel general-purpose theorem was recently stated for the analysis of linear circuits [19], which is also applicable to the measurement field for loading-effect reduction [20]. According to this theorem, any current can be determined as an equivalent voltage divided by an equivalent impedance, and any voltage as an equivalent current multiplied by an equivalent impedance.…”