The Task of Measuring Voltage

• In the world of electricity, the typical measurement is that of voltage. A volt meter will measure the voltage, usually within a range of up to hundreds of volts. In the power industry, the transmission of electricity occurs at thousands and tens of thousands of volts. This would destroy nearly all typical voltmeters. How then, do technicians measure the high voltages they encounter every day? The trick is to use a potential transformer.
  
  

The Potential Transformer

• The potential transformer works along the same principle of other transformers. It converts voltages from high to low. It will take the thousands of volts behind power transmission systems and step the voltage down to something that meters can handle. These transformers work for single and three phase systems, and are attached at a point where it is convenient to measure the voltage.
  
  

What Gives a Transformer Potential?

• The biggest feature that a potential transformer has over regular transformers is that the voltage conversion is constant and linear. That is to say, if the first day of operation 50,000 volts is stepped to 50 volts, then on the last day of operation 50,000 steps to 50 volts. Linearity states that when the voltage drops in a linear fashion, then the stepped down voltage drops accordingly. This features ensures that the meter will scale accordingly. The potential transformer makes the measure of very high voltages much more easier.