Temperature Measurement of Microscopic Areas Within a Simulated Head/Tape Interface Using Infrared Radiometric Technique

Abstract
This study concerns the infrared measurement of steady-state and transient temperatures of microscopic areas within the contact region formed by a magnetic tape passing over a simulated recording head. This research demonstrates that the tape surface temperature can be measured within specific limits of response time and sensitivity. Due to its high tranmissivity in the relevant infrared band, sapphire was chosen as the material to be used in the fabrication of a simulated recording head. A Barnes RM2A infrared microscope was the principle radiometer used, while a best effort was made in scanning with an AGA Thermovision 750. The friction force versus load characteristics of the head-magnetic tape interface were also observed. The high speed measurements were divided into two regimes; non-contact hydrodynamic film region, and tape-head contact regime. The temperature measurements displayed a strong correlation with the measured friction force versus load curve. Almost no temperature rise was found in the noncontact hydrodynamic film region while a temperature rise of a few degrees Celsius was found when there was tape-head contact. The results with the AGA Thermovision 750 were consistent with the measurements obtained with the Barnes RM2A.