A novel technique for measuring head-tape spacing

The effective magnetic head-tape spacing was determined by fitting the measured tape-noise spectral density to the Wallace exponential spacing-loss function. The advantage of this approach over the customary method of measuring the spectrum of the recorded signal is that no corrections are necessary for recording or demagnetization losses. Calibration was done with a spacing shim; good experimental fit to a straight line was obtained in the semi-logarithmic plots.