6 Apparatus6.1 GeneralThe system for metrological confirmation of the tensile-testing machine shall be in accordance with ISO10012一1.6.2 CRE machine, having the following characteristics:a) Capable of operating at a constant-rate-of-extension of (100 1 10) mm/min;b) capable of gauge length to be set to (100 1 1)mm;c) provided with means for recording the force applied to the test specimen during the tear test;d) under conditions of use, the accuracy of the apparatus shall be class 1 of ISO 7500一1 The error of theindicated or recorded maximum force at any point in the range in which the machine is used shall notexceed 1 1%,and the error of the indicated or recorded jaw separation shall not exceed 1 1 mm;e) if recording of force and extension is obtained by means of data acquisition boards and software, thefrequency of data collection shall be at least 8 per second.If a class 2 tensile testing machine has to be used, this shall be stated in the test report.6.3 Clamping device, comprising the two jaws of the machine, the central points of which are in the line ofpull, the front edges at right angles to the line of pull and the clamping faces in the same plane.The jaws shall be capable of holding the test specimen without allowing it to slip and designed so that theydo not cut or otherwise weaken the test specimen.The width of the jaws shall preferably be 75 mm,but shall not be less than the width of the test specimen.6.4 Equipment for cutting out test specimens, preferably a hollow punch or template to give testspecimens of the dimensions shown in figure 1.7 Atmosphere for conditioning and testingThe atmospheres for preconditioning, conditioning and testing shall be as specified in ISO 139.8 Preparation of test specimens8.1 GeneralFrom each laboratory sample two sets of test specimens shall be cut, one set in the warp direction and theother in the weft direction.