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Establishment of an International Scale for Instrumented Charpy Testing: comparison between NIST and LNE



Enrico Lucon, Christopher N. McCowan, Raymond L. Santoyo, Stephane Lefrancois


As a contribution to the establishment of an international scale for instrumented Charpy testing, aimed at ensuring that impact forces are obtained more accurately, NIST and Laboratoire National de métrologie et d’Essais (LNE, France) have participated in an interlaboratory comparison of instrumented impact tests on reference specimens of different energy levels from seven certified verification batches. In both locations, tests have been performed using nominally identical Charpy machines and the same instrumentation (Charpy striker and acquisition system). The comparison between NIST and LNE test results has revealed statistically significant differences, particularly in terms of absorbed energies and instrumented forces. The reasons for such discrepancies are unclear, although a malfunction of the acquisition system during the tests at LNE and possible differences in the surface finish of the machine anvils and supports in the two labs can be listed as contributing factors.
Technical Note (NIST TN) - 1875
Report Number


Absorbed energy, instrumented Charpy testing, instrumented forces, interlaboratory comparison, lateral expansion, LNE, NIST, reference Charpy specimens, surface finish


Lucon, E. , McCowan, C. , Santoyo, R. and Lefrancois, S. (2015), Establishment of an International Scale for Instrumented Charpy Testing: comparison between NIST and LNE, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed July 14, 2024)


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Created April 1, 2015, Updated November 10, 2018