Accuracy of the measurement questioned.
Measuring instruments are usually classified according to standards and accuracy. Accuracy is an important indicator for being able to usefully build on a solid measurement result in the analysis and its resulting measures. However, it can be observed that although the measuring devices used correspond to a required accuracy class, the necessary sensors are often less in focus.
It can be seen that although class A measuring devices used in power quality applications correspond to a data sheet accuracy of 0.1% for U/I and 0.2S at the energy meter, upstream current transformers are often designed significantly worse (e.g. 0.5% or worse). And this is apart from the fact that not only accuracy plays a role in power quality measurements, but also the inevitable compatibility against harmonics – one of the modern and growing main players in power quality. Read more