Oscilloscopes measure current and voltage and, through the magic of mathematics, calculate power. Unfortunately, power comes in a large number of guises: instantaneous, real, apparent, and reactive. This plethora of power terms often leads to confusion. This article explains how to use the Power Analysis software package on the Teledyne LeCroy HDO 6000 scope to eliminate the need to set up proper math operations.
Oscilloscopes, whether analog or digital, are voltage responding instruments. Current is measured using a suitable transducer, usually a current probe or resistive shunt. The oscilloscope display is the instantaneous function of voltage or current vs. time. The product of these quantities is instantaneous power.
A basic line power measurement is shown in Figure 1.
Figure 1: The elements of a power measurement (instantaneous voltage, current, and power) shown on an HDO 6000 oscilloscope equipped with the Power Analysis option. Real and apparent power are automatically computed and displayedThis article appears in its entirety on
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