General Problems of Metrology and Measurement Technique Static Component of Temperature Error in the Strain-Gauge Balance: Determination of the Temperature Sensitivity Coefficient

• Published in: Measurement techniques 2022, Vol.64 (10), p.794-800
• Main Authors: Gorbushin, A. R., Krapivina, E. A., Tytyk, M. N.
• Format: Article
• Language: English
• Subjects: Aircraft; Aircraft models; Analytical Chemistry; Characterization and Evaluation of Materials; Coefficients; Measurement Science and Instrumentation; Measurement techniques; Microbalances; Physical Chemistry; Physical factors; Physics; Physics and Astronomy; Sensitivity; Strain gage balances; Strain gauges; Wind tunnel testing; Wind tunnels
• ISSN: 0543-1972; 1573-8906
• DOI: 10.1007/s11018-022-02006-7

In experimental studies of aircraft models in wind tunnels, high-precision strain-gauge balances are used, whose accuracy depends on temperature. We have analyzed and quantified the main physical factors causing variation in the readings of the strain-gauge balance under the influence of temperature. The influence of the static component of the temperature error in the readings of the strain-gauge balance is considered. A method is described for introducing temperature corrections to the readings of a strain-gauge balance using the temperature sensitivity coefficient. A method has been developed for determining the temperature sensitivity coefficient (TSC), which is used in the process of testing in wind tunnels in the absence of a specialized calibration stand with a heat chamber. We describe the experimental equipment and the process of studying six-component intramodel strain-gauge balances. The effect of the static temperature component on readings is quantitatively determined. The typical TSC value was approximately 0.04%/°C. The change in readings of a strain gauge balance when its temperature changes by 3–4°C exceeds the standard deviation obtained when the balance was calibrated. This change in readings is a systematic temperature error of a strain gauge balance and should be excluded from the results of load measurements by the balance in the form of a correction to the sensitivity coefficient or electrical signal. The method for determining the temperature sensitivity coefficient of the balance force components is verified by the results of weighing the aircraft model and the metric parts of the longitudinal and normal components of the balance force in the wind tunnel.