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Comparison of Electrical Output Format Options for the Analysis of Strain-Gage Balance Calibration DataFundamental characteristics of three gage output formats are discussed that may be used to both interpret and analyze wind tunnel strain-gage balance data. The first output format uses raw outputs, i.e., absolute voltage measurements, for the analysis. This choice requires an intercept term in the regression model of the outputs if the Iterative Method is chosen for the load prediction. Raw outputs can be used for the analysis of all known output characteristics as long as the Iterative Method is applied. However, raw outputs cannot be used to analyze data of a balance with bi-directional outputs if the Non-Iterative Method is chosen for the analysis. The second output format, i.e., difference type 1, uses the difference between raw outputs and the natural zeros of the balance gages for the analysis. In this case, the use of the intercept term becomes optional. Analysis results for difference type 1 will exactly match analysis results obtained by using raw outputs as long as identical math models are used for the regression analysis. In addition, difference type 1 may be used to analyze data of a balance with bi directional outputs if an analyst prefers to process data using the Non-Iterative Method. The third output format, i.e., difference type 2, uses the difference between raw outputs and the outputs of the zero load point of a load series for the data analysis. The application of this format is only recommended if the maximum magnitude of all tare loads of a given balance calibration data set is less than two percent of capacity. Data from the calibration of a force balance is used to illustrate the application of the three gage output formats.
Document ID
20190026532
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Ulbrich, N.
(Jacobs Engineering Group Mountain View, CA, United States)
Date Acquired
June 20, 2019
Publication Date
June 17, 2019
Subject Category
Research And Support Facilities (Air)
Aerodynamics
Report/Patent Number
ARC-E-DAA-TN66186
Meeting Information
Meeting: AIAA Aviation and Aeronautics Forum (Aviation 2019)
Location: Dallas, TX
Country: United States
Start Date: June 17, 2019
End Date: June 21, 2019
Sponsors: American Institute of Aeronautics and Astronautics (AIAA)
Funding Number(s)
CONTRACT_GRANT: NNA16BD26C
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
Single Expert
Keywords
Wind Tunnel Strain-Gage Balance
Calibration
Data Analysis
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