Which is the optimum frequency range for partial discharge measurements in rotating machinery


The frequency range should be under 10MHz, due to signal absorption effects (dispersion) signals from deep in the winding do not arrive at the coupler. 1nF capacitors and RFCT's diminish the attenuation effect.

Harmful high intensity sparking or a thermal discharge type does not contain significant high frequency signal energy, measurements of up to max. 5 MHz are recommended. If not doing so, this discharge type remains unidentified.