If you mostly deal with DC current, you might not think much of root mean square or RMS measurements. Sure, you’ve seen meters that have “true RMS” settings, but what does it mean? If you don’t know — ...

Total harmonic distortion (THD) is the harmonic distortion present in a signal, defined as the ratio of the root-mean square (RMS) amplitude of a set of higher harmonic frequencies to the RMS ...