Sliding contact energy measurement using a calibrated acoustic emission transducer

Acoustic emission (AE) transducers are commonly used to monitor the intensity of mechanical contacts in various sliding applications including magnetic head-disk interfaces (HDI). The authors introduce a method to obtain the electrical energy of the AE transducer from the output signal voltage. Calibration experiments were run to determine the calibration factor for converting the AE electrical energy to mechanical energy that is released during mechanical contacts at the HDI. Analytical models to calculate the energy released as a result of mechanical contacts arising from slider-disk interaction, from the presence of particulate contamination at the HDI, and those from head-disk interactions during dynamic load/unload (L/UL) in L/UL drives are presented. Experimental results for some of the cases described by the models are presented.