Abstract
An experimental study about the relative merits of using a high-speed digital-acquisition system to measure directly the strain-gage resistance rather than using a conventional Wheatstone bridge, is carried out.
Both strain gages, with a nominal resistance of 120 Ω and 1 kΩ, are simulated with precision resistors and the output signals were acquired over a time of 48 and 144 hours; furthermore, the effects in metrological performances caused by a statistical filtering are evaluated.
The results show that the implementation of the statistical filtering gains a considerable improvement in gathering straingage-resistance readings. On the other hand such a procedure causes, obviously, a loss of performance with regard to the acquisition rate, therefore to the dynamic data-collecting capabilities. In any case the intrinsic resolution of the 12-bit a/d converter, utilized in the present experimental analysis, causes a limitation for measurement accuracy in the range of hundreds μ m/m.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Jedju, T.M., “A Data Acquisition and Control System Based on the New Commodore Pet Microcomputer,”Rev. Sci. Instr.,50 (9),1077–1079 (1979).
Estler, R.C., “Data Acquisition and Control System Based upon the Rockwell AIM-65 Microcomputer,”Rev. Sci. Instr.,51 (10),1428–1430 (1980).
McConnell, K. andAbdelhamid, H., “Unleashing a Microcomputer in the Laboratory,”Experimental Techniques,7,22–24 (Jan.1983).38–40 (Feb. 1983), 28–30 (March 1983).
Lu, W.Y., “A Personal Computer Base Testing System,” V. Int. Cong. on Exp. Mech., Montreal, 245–249 (June 1984).
Lu, W.Y., “Use of the Personal Computer for Automated Testing,” 1985 SEM Fall Conf. on Exp. Mech., 141–145 (Nov. 1985).
Teaford, W.J., “Computer Field Data Acquisition,” Proc. Tech. Sess. SESA, Silver Spring, 26–27 (1976).
Kreuzer, M., “Comparing the Effect of Lead and Switch Reistances on Voltage- and Current-fed Strain-gage Circuits,”Rep. in Appl. Meas.,1,13–18 (1985).
Howland, H.J., “An Integrated Software/Hardware Approach to Experimental Stress Analysis,” VII Int. Conf. on Exp. Stress Analysis, 263–270 (May 1986).
Kreuzer, M., “How to Avoid Errors Caused by Heat Effects in Strain Gage Measurements when Using Scanning Units,” VII Int. Conf. on Exp. Stress Analysis, 447–454 (1986).
Versnel, W.J., “Compensation of Lead-wire Effects with Resistive Strain Gages in Multi-channel Strain Gauge Instrumentation,” VII Int, Conf. on Exp. Stress Analysis, 455–464 (1986).
Boswell, R.S. and Payne, M.L., “Development and Application of Special Purpose Data Acquisition System for Strain Gage Testing of Threaded Tubular Connections Used in Oil Field” 1987 SEM Spring Conf. on Exp. Mech., 158–163 (June 1987).
Williams, M. andMcFetridge, G., “Unbalanced-bridge Computational Techniques and Accuracy for Automated Multichannel Strain Measuring Systems,”Experimental Techniques,7,32–37 (1983).
Cappa, P., “Limits of Inaccuracy of Automatic Direct Systems for Strain Gage Data Readings Based on a Low Cost Switch Control Unit,” 1989 SEM Spring Conf. on Exp. Mech., 539–543 (May 1989).
Nelson, E.J., Sikorra, C.F. andHoward, J.L., “Measuring Strain Gages Directly Without Signal Conditioning,”Experimental Techniques,7,26–28 (Sept.1983).
Hillen, R.E. and De Witt, R.J., “Measuring the Coefficient of Thermal Expansion of Composites Using the Strain Gage Method,” 1987 SEM Spring Conf. on Exp. Mech., 158–163 (June 1987).
Cappa, P., “Limits of Accuracy of Microcomputer-controlled Scanning Systems for Strain Gage Data Readings,” VI Int. Cong. on Exp. Mech., 469–473 (June 1988).
Cappa, P., “Limits of Inaccuracy of Automatic Direct Systems for Strain Gage Data Readings Based on a Low Cost Switch Control Unit,” Experimental Techniques,13–15 (Sept. 1989).
Cappa, P., McConnell, K. and Zachary, L., “An Experimental Analysis of the Zero Shift Values of Automatic and Inexpensive Strain Gage Instrumentation System,” 1990 SEM Spring Conf. on Exp. Mech., 205–210 (June 1990).
Anon., “HP-IB Improving Measurements in Engineering and Manufacturing. A Collection of Useful Technical Information,” Hewlett-Packard Publication 3592-0058.
Anon., “Tutorial Description of the Hewlett-Packard Interface Bus,” Hewlett-Packard Publication 5952-0156.
Branca, F.P., Cappa, P. and Steindler, R., “Accelerated Fatigue Tests of Wire Ropes,” Wire Industry, 654–658 (Sept. 1990).
Taylor, J.R., “An Introduction of Error Analysis. The Study of Uncertainties in Physical Measurement, Univ. Science Books, Mill Valley (1981).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cappa, P., Del Prete, Z. An experimental analysis of accuracy and precision of a high-speed strain-gage system based on the direct-resistance method. Experimental Mechanics 32, 78–82 (1992). https://doi.org/10.1007/BF02317990
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02317990