A Proposed Estimation of the Expanded Uncertainty of Charpy Impact Testers

Authors

  • A. Abu-Sinna Dr.
  • Saher R. Hassan Force and Material Metrology Laboratory (FMMD), National Institute of Standards (NIS) Giza, Egypt

DOI:

https://doi.org/10.24203/ajas.v8i5.6326

Keywords:

Calibration, Impact Testers, Uncertainty, Direct Method

Abstract

Uncertainty estimation is one of the very delicate tasks in the field of measurements. For the purpose of calibration of Charpy impact testing machines, it is necessary to evaluate and identify the expanded uncertainty. Factors affecting the uncertainty estimations are; the uncertainty of reference force and length measuring devices and its long-term instability (drift), machine resolution, rated energy error, indicated energy error, losses due to the drag of the pointer, friction losses in the bearing and air resistance, and other geometric parameters. In this study, the uncertainty estimation of the Charpy impact machines is based on the direct verification used in the BS DIN ISO 148-2 standard.

References

Siewert, T. A., Manahan, M. R, McCowan, C. N., Holt, J. M., Marsh, E J., and Ruth, E. A., "The History and Importance of Impact Testing, Pendulum Impact Testing: A Century of Progress”, STP 1380, T. A. Siewert and M. E Manahan, Sr., Eds., American Society for Testing and Materials, West Conshohocken, PA, 2000.

BSI DIN EN 10045, Part2, Verification of pendulum impact testing machines, direct verification method.

BS EN ISO 148-2:2016, Metallic materials - Charpy pendulum impact test - Part 2: Verification of testing machines.

A. A. Hawam, E. H. Hasan, G. Mohamed, M. Ahmadein, “The resolution uncertainty associated with digital indications revisited: The inclusion of the quantization effect and the impact of noise presence in the estimation process”, (2018) Metrologia, 55 (6), pp. 883-892.

Kyle Wayne Strabala, “The Effects of Combined Compression and Aging on the Properties of Glassy Polycarbonate”, Engineering Mechanics, Department of Engineering Mechanics Dissertations & Theses, University of Nebraska, 2009.

EAL-G22-1996, Uncertainty of calibration results in force measurements.

A. Sawla, Uncertainty of calibration results of tension/compression testing machines, PTB, March 1998.

ISO GUM, Guide to the expression of uncertainty in measurement, 1993.

Diedert Peschel and Dietmar Mauersberger, Determination of the friction of aerostatic radial bearings for the lever- mass system of torque standard machines, XIII IMEKO WOLD CONGRESS, September, 5-9, 1994, Torino, Italy.

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Published

2020-10-30

How to Cite

A. Abu-Sinna, & Hassan, S. R. (2020). A Proposed Estimation of the Expanded Uncertainty of Charpy Impact Testers. Asian Journal of Applied Sciences, 8(5). https://doi.org/10.24203/ajas.v8i5.6326