Carbon fibres, Mechanical properties of materials, Tensile strength, Tensile testing, Plastics, Impregnated materials, Yarn, Modulus of elasticity, Strain, Tensile strain, Loading, Reinforcing materials, Composite materials, Test equipment, Test specimens, Specimen preparation, Linear density, Size, Determination of content, Density, Precision, Epoxy resins, Extensometers, Yarn testing