EN 61788-4:2016

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Apparatus
6 Specimen preparation
7 Data acquisition and analysis
8 Uncertainty and stability of the test method
9 Test report
Annex A (informative) - Additional information relating
        to the measurement of RRR
Annex B (informative) - Uncertainty considerations
Annex C (informative) - Uncertainty evaluation in test
        method of RRR for Nb-Ti and Nb3Sn composite
        superconductors
Bibliography
Annex ZA (normative) - Normative references to
         international publications with their
         corresponding European publications

IEC 61788-4:2016 specifies a test method for the determination of the residual resistance ratio (RRR) of Nb-Ti and Nb₃Sn composite superconductors with Cu, Cu-Ni, Cu/Cu-Ni and Al matrix. This method is intended for use with superconductor specimens that have a monolithic structure with rectangular or round cross-section, RRR value less than 350, and cross-sectional area less than 3 mm². In the case of Nb₃Sn, the specimens have received a reaction heat-treatment. This fourth edition cancels and replaces the third edition published in 2011. This edition constitutes a technical revision.