Technology Blog
The Electrical metering instrument technology has come a long way from what it was more than 100 years ago. From the original bulky meters with heavy magnets and coils, there have been many innovations that have resulted in size & weight reduction in addition to improvements in features and specifications. Resolution and accuracy of the …
Just like Binomial Distribution, Poisson Distribution is also a random variable distribution. We apply Poisson distribution in any one of the following cases: n, the number of times that the experiment is conducted is sufficiently large. Occurrence of success is rare. Occurrence of success is frequent. In Poisson distribution, values of random variable are the …
Phantom Loading When a energy meter is designed for high current loads, it is uneconomical to arrange such loads for testing purposes as it involves a considerable waste of time and power. To avoid this problem “phantom” or “fictitious” loading is done. In phantom loading, pressure coil is excited from normal supply voltage and current …
The ranges of an AC ammeter can be extended by using current transformer CT. To measure high currents, CT’s are used in conjunction with measuring instruments. They find wide spread applications in protection circuits of power system for operation of relays. Advantages of CT’s in extending the range are : Metering circuit is isolated from …
To measure the 3-φ power in a balanced circuit, the method or main apparatus used here are 2 CT’s and one Wattmeter. The details of the apparatus required for this measurement are as follow: Wattmeter 600V, 10A, UPF -> 1 no. Ammeter (0-10)A MI -> 1 no. Voltmeter (0-600)V MI -> 1 no. Current Transformer …
Potentiometer A Potentiometer is a electrical device used to measure unknown voltage by comparing it with a known voltage. It comprises of a slide wire of uniform cross-section and hence uniform resistance along its length. A calibrated scaling cm and fraction of cm is placed along the slide wire. Before using the potentiometer it should …