ISO 22074-8 pdf download Railway infrastructure — Rail fastening systems — Part 8: Test method for vertical stiffness The calibration of displacement-measuring instruments shall be in accordance with ISO 9513. 6Test procedures for pads 6.1Static test procedure for pads6.1.1 Principle A force is applied normal to the test pad and the displacement is measured.6.1.2Apparatus 6.1.2.1 Controlled temperature test area, area...