This Technical Specification specifies the conditions, apparatus and procedure for determining the distribution of tensile strength and tensile strain to failure of ceramic filaments in multifilament tows at high temperature in air, vacuum or a controlled inert atmosphere.This Technical Specification applies to tows of continuous ceramic filaments, which are assumed to act freely and independently under loading and behave linearly elastic up to failure.Two methods are proposed depending on the temperature of the ends of the tow:a)hot end method;NOTE 1The application of the hot end method is restricted by ceramic glues with sufficient shear strengths at the test temperature. Current experience with this technique is limited to 1 300 °C, because of the maximum application temperature of ceramic glues.b)cold end method.NOTE 2The cold-end method is limited to 1 700 °C in air and 2 000 °C in inert atmosphere because of the limits of furnaces.Both methods allow for a failure rate in the determination of distribution of tensile strain and tensile strength.