Quantification and Modeling the Effects of Thermal Shock on Combustion Pressure Transducers

This study's objective was to characterize thermal-shock errors on a specific Kistler pressure transducer and to determine if a thermal-shock correction algorithm using transducer surface temperature could be developed. Atmospheric measurements were made using a thermal-shock rig which intermittently exposed the transducer to a known heat flux while maintaining atmospheric pressure on the transducer diaphragm. Any change in output is attributable to thermal shock. Surface temperature was measured using a separate eroding-type surface thermocouple. The data showed a strong correlation between heat-flux induced temperature change and thermal shock and were used in a least-squares error estimation algorithm to create a model of the thermal shock as a function of transducer surface temperature. The model was calibrated using baseline measurements and tested against measurements made at different heat flux intensities and exposure duration and frequency. The model was able to remove approximately 95% of the error under all tested conditions.