Uncertainty evaluation for the dynamic calibration of pressure transducer

The uncertainty of dynamic calibration for pressure transducer is a key indicator of its dynamic measurement precision. A novel grey method (GM) was proposed to evaluate the dynamic calibration uncertainty of pressure transducer. Firstly, a sine pressure generator was used to produce required sine pressure signal to drive the calibrated pressure transducer and obtain output of transducer. Secondly, using the grey relational analysis to deal with the measurement sequences outputted, a weighted value sequence was obtained. Thirdly, a grey model was established to calculate the calibration uncertainty of appointed frequency. Finally, a weighted least-square fitting method was applied to do fitting with the calibration uncertainty of appointed frequency, and then a dynamic calibration uncertainty model was established. An experimental verification under the calibration condition of changing amplitude and unchanging amplitude was set up. Grey method and Huang method (HM) were used to process the output of pressure transducer separately. The results show that the curve models of dynamic calibration uncertainty are consistent with each other in the setting condition. What is more, under changing amplitude, the relative error of calibration uncertainty obtained by the two methods is superior to 6% at appointed frequency points and is also less-than 10% at testing frequency points. Under unchanging amplitude, the relative error is less than 5% at most of frequency points and is superior to 0.018% at some testing frequency points. Based on the above analysis, it can be approved that the grey method can evaluate the dynamic calibration uncertainty of pressure transducer reliably.