Contamination Test Trace

Contamination – Shown as irregular spikes with the leading edge rising (the ball must climb the contaminating speck before falling off the back side).










Misalignment Test Trace

Raceway misalignment – Sinusoidal torque variation over 360° is indicative of slight raceway misalignment.

VCM Test Trace

Voice coil motor (VCM) – This is an automatic test of the motor efficiency over the entire length of stroke of the motor. The test automatically reverses when the hard stop is encountered and the reverse stroke is overlaid as a reversed trace so that features will align correctly. Built-in current measurement allows display of Kt (gm-cm per amp).

Lobing Test Trace

Lobing – Two different sinusoidal variations with periods much shorter and much longer than 360° are typical. This example is plotted in MS Excel using direct test export feature.