JPS6459114A - Smoothness measurement - Google Patents

Abstract

PURPOSE:To measure smoothness easily and accurately in a short time, by a method wherein the surface to be measured of a test sheet is brought into contact with the surface of a sheet of the same type or a reference surface and is pressed at a fixed pressure to measure a tensile force necessary for causing a slide therebetween. CONSTITUTION:A weight W is placed on a test paper S' and a rotating force is transmitted to a pickup roll 1 with a commutator motor 3 through a timing pulley 4 to pull an upper test paper S with the pickup roll 1 together with the weight W. A voltage applied to the commutator motor 3 is raised gradually until the paper S' begins to slide and a tension currently working on the paper is detected with a strain gauge 2, a detection signal of which is outputted to a CPU or the like outside from a slip ring 5 to record. The tension pulling the test paper S' is increased with a rise in the voltage applied to the motor 3 but the tensile force falls sharply when the upper test paper S' begins to slide with respect to the test paper S fixed. Thus, the record of the tensile force gives one peak, thereby indicating the max. static friction force by the height of the peak.