Tape asperity compliance measurement using a pneumatic method

The effects of asperity compliance on the head/tape interface is investigated for various magnetic tapes with different surface roughness characteristics and structure. Laser interferometry is used to obtain the asperity compliance curves for each tape by relating spacing and contact pressure at the head/tape interface with the spacing and contact pressure between a glass optical flat and tape. The Greenwood-Williamson model for contact between rough surfaces is used to "curve fit" the experimental data. The effect of visco-elasticity on asperity compliance is investigated.