ISO 2759:2014 pdf free
ISO 2759:2014 pdf free.Board一Determination of bursting strength
The apparatus should be fitted, or able to be fitted, with suitable test points to facilitate checking of the fluid pumping rate, calibration of the maximum pressure-measurement and display system and calibration of the clamping pressure-indicating device where fitted.
Calibration shall be carried out before initial use and at sufficiently frequent intervals to maintain the specified accuracy. Wherever possible, calibration of the pressure-sensing device should be carried out with it mounted in the same position it occupies on the apparatus and preferably on the apparatus itself.If a pressure sensor is accidentally subjected to pressure beyond its rated capacity, it shall be recalibrated before further use.
Aluminium foils of various thicknesses may be available for use as test pieces of known burst value. Such devices are a useful means of checking the overall function of an instrument but, since the behaviour of foil under stress is unlike that of paper, they should not be used as calibration standards.
If necessary, zero the hydraulic- pressure-indicating device according to the manufacturer’s instructions.Apply hydraulic pressure until the test piece bursts. Retract the piston until the diaphragm is below the level of the diaphragm-clamping plate. Read the indicated bursting pressure to the nearest kilopascal. Release the clamp and prepare the instrument for the next test. Readings shall be rejected when visible slippage of the test piece (as shown by movement of the test piece area outside the clamps or by creasing of the test piece in the clamped area) has occurred. In cases of doubt, the use of a larger test piece will frequently establish whether slippage is occurring. Readings shall be rejected if the type of failure (for example, severance at the periphery of the test zone) indicates that the test piece was damaged by excessive clamping pressure or rotation of the clamps during clamping.
If separate results are not required for each surface of the board in contact with the diaphragm, 20 valid tests shall be carried out to obtain the result. If separate results are required for the two surfaces of board, a minimum of 10 valid tests shall be carried out on each side.ISO 2759 pdf download.