"A method and equipment are described for determining the surface parameters of contact required for heat transfer calculations. In this method, the output of a surface analyzer for one surface is recorded on one channel of magnetic tape and the output for the other surface of the contact pair on a second channel. The tape is played back to an analog computer which then integrates the analog voltage to compute the void volume thickness, the number of contact points, and the ratio of metallic contact area to the total area."