This part of ISO 1924 specifies a method for measuring tensile strength, strain at break and tensile energy absorption of paper and board, using a testing machine operating at a constant rate of elongation (20 mm/min). This part of ISO 1924 also specifies equations for calculating the tensile index, the tensile energy absorption index and the modulus of elasticity.Testing in conformance with this part of ISO 1924 always includes the measurement of tensile strength.Measurement or calculation of other properties is subject to agreement between the parties concerned.This part of ISO 1924 is applicable to all papers and boards, including papers with a high stra