TRMS | The True effective value (true RMS) does not actually differ from the effective value. However, in the development of electrical measuring devices, the RMS value was often displayed even though it was not measured. The arithmetic mean value of a sinusoidal voltage was measured. The conversion factor for a 50 Hz sinusoidal alternating voltage was immediately taken into account when measuring the series resistors. However, since in modern electronics and electrical engineering the voltage forms deviate significantly from the sinusoidal voltage, the difference to devices that actually work according to the mathematical principles quickly became apparent. Devices that work according to the mathematical principles are therefore labeled as true RMS (true root mean square).
