ISO 14087:2011 pdf download.Leather -Physical and mechanical tests -Determination of bending force.
5.1.3 Means of measuring the bending force. The rotation of the specimen causes it to be pressed against a vertical metering bar. (See Figure 2.) The bar is connected to a load cell that allows measurement of forces up to 10 N (optionally, 1 N for very flexible materials) with a minimum resolution of 0,1 % and a maximum deviation of 0,1 %. The bar design shall exhibit a sharp edge (R = 0.05 ± 0,01 mm) and a width of at least 30 mm The weight of the bar shall not influence the measured value.
The distance between the bar and the pivot point shall be adjustable in a range from 0,1 mm to 50 mm with an accuracy of 0,1 mm. At the start of the measurement, the specimen is moved towards the bar until contact is made and a defined preliminary force is reached. This preliminary force shall be able to be adjusted with an accuracy of 1 mN. When the preliminary force is reached, the measurement shall start (angle - 00 and force — preliminary force setting). The evaluation unit shall ensure measurement of the force at one or more previously defined angles. These angles shall not be identical to the maximum angle of rotation. The measuring apparatus shall ensure that all significant parameters (force, length, speed) can be checked, calibrated and restored. It is recommended that the measured data (raw data and parameter settings) are able to be electronically archived.
The distance between the bar and the pivot point shall be adjustable in a range from 0,1 mm to 50 mm with an accuracy of 0,1 mm. At the start of the measurement, the specimen is moved towards the bar until contact is made and a defined preliminary force is reached. This preliminary force shall be able to be adjusted with an accuracy of 1 mN. When the preliminary force is reached, the measurement shall start (angle - 00 and force — preliminary force setting). The evaluation unit shall ensure measurement of the force at one or more previously defined angles. These angles shall not be identical to the maximum angle of rotation. The measuring apparatus shall ensure that all significant parameters (force, length, speed) can be checked, calibrated and restored. It is recommended that the measured data (raw data and parameter settings) are able to be electronically archived.
