W136 — Why true RMS is important for Clamp-Meters
Measuring current accurately is a difficult job in today’s industrial plants and offices. More and more personal computers, adjustable speed drives and other types of equipment that draw current in short pulses rather than at a steady levelTroubleshooting the electrical service feeding
adjustable speed motor loads can be difficult if you don’t have the right tools. New solid state motor drives and heating controls often conduct non-sinusoidal (distorted) current. In other words, the current occurs in short pulses rather than the smooth sine wave drawn by a standard induction motor. The current wave shape can have a drastic effect on a current clamp reading.