基本信息
摘要：A method of and an apparatus for measuring the abrasiveness of a floppy disc are disclosed. The apparatus comprises a head 7 adapted to be urged into contact with a floppy disc whilst the head and the disc move relative to each other. The surface 2 of the head which is urged into contact with the floppy disc is provided with a thin film of electrically conductive material e.g. of nickel-chrome alloy 100 to 400 A thick. Means are provided for measuring the electrical resistance of the thin film on the head and thus change in the film's electrical resistance can be monitored. Such change is related to the abrasiveness of the disc and calculations can be undertaken to determine the abrasiveness from the change in resistance measured. As described the head comprises an alumina ceramic substrate 1 with a flat upper surface 2 bounding a recess 3. Leads 6 are soldered to nickel-coated regions 5 connected to the alloy film. Temperature variations are compensated by supplying the head 7 and a resistor 13 at the same temperature in series from a constant current source 8.
摘要附图：
