BS EN ISO 8031:2020 pdf free.Rubber and plastics hoses and hose assemblies——Determination of electrical resistance and conductivity.
BS EN ISO 8031 To determine the resistance of conductive, antistatic and non-conductive hose1), the test should preferably be made with an instrument specifically designed for measuring insulation resistance, having a nominal open-circuit voltage of 500 V d.c., or with any other instrument known to give comparable results. The instrument shall be sufficiently accurate to determine the resistance to within +10 % unless specified otherwise. During the test, not more than 3 W shall be dissipated in the specimen, to prevent erroneous results due to effects of temperature. The power dissipated shall be determined by the square of the open-circuit voltage divided by the measured resistance.The resistance values obtained will vary with the applied voltage, and errors may occur when low test voltages are involved. In cases of dispute, the voltage applied to the test piece shall be not less than 40 V,except where this conflicts with the requirement not to dissipate more than 3 W in the test piece. For tests requiring the measurement of the electrical continuity between end fittings or through
continuous internal or external bonded wires, the instrument used shall be an ohmmeter sufficiently accurate to determine the resistance to within +10 %.
For tests where, according to the product standard, determination of the electrical continuity between the end fittings of a hose assembly is required, without measurement of the actual electrical resistance, a 4,5 V battery in combination with a 4 V ([0,3 A) test lamp can be used. For determination of the electrical resistance through the hose wall (required by some hose product standards for hoses used in explosive atmospheres), the instrument used shall be an ohmmeter with a capacity of 1012 n and the measurement shall be made at 500 V d.c. The instrument shall be sufficiently accurate to determine the resistance between the lining and the cover as measured through the hose wall to within +5 %. BS EN ISO 8031 pdf download.