Estimation of the service life of fibres after proof testing: a perspective

The author shows that different predictions of the service life of optical fibres can be derived from a given set of assumptions. Short term tests cannot be relied upon to verify the accuracy of any analysis. The sensitivity of the predictions to the stress corrosion index and the constant B suggests that rigorous testing is needed to obtain accurate mean values and their respective confidence limits for the conditions expected in service. Testing techniques need to be standardised to enable comparison of the stress corrosion constants obtained in different places to be made