Intensity measurements of an electric current

The market offers a wide variety of devices for measuring electrical current. Various measurement methods are also available. The choice of equipment to be used, and of the most appropriate method, is determined by the type of measurement required, and by the intended use of the information obtained. In fact, the approach differs according to whether the measurements are required for functional tests or to check compliance with a specification or standard, for laboratory measurements, for one-off or repetitive measurements carried out using an automated bench, for measurements of high currents or low current intensities, carried out in continuous mode, at low frequency or at higher frequency.

In the case of alternating currents, the nature of the parameter to be measured (RMS value, average value after rectification, etc.) is also a decisive factor in the choice of device, especially when it comes to signals affected by distortion. The problem of signal shape is discussed in 1 .

The main types of ammeter in existence are presented in 2 , each with a description of its operating principle and main specifications. Particular emphasis is placed on digital devices, which, as a result of unceasing progress in the field of electronics, have invaded the market to the detriment of analog devices. Indeed, the performance of the components and systems around which they are built, the wide range of functions they perform, their robustness and their increasingly attractive price tag have made their use almost universal. Some of them offer the possibility of sampling the signal, enabling mathematical analysis of it and thus giving access to all its characteristics.

The 3