Design optimization of differential air pressure sensor calibration setup for sensitivity minimization to thermal gradient

This paper focuses on the thermal stability of a high performance, low-range calibration setup for differential air pressure sensors. The setup is a dual parallel chamber design with the full range of ±320 Pa, which can be translated to a temperature mismatch of only about 0.93°C between the chambers. Due to the limitations of existing temperature measurement technology, we propose a finite element model (FEM) analysis to study the effect of thermal gradient on the calibration setup. The model setup includes the dual parallel chamber design inside a conventional climate chamber. From the conducted analysis we observe that, due to the non-ideal heat distribution inside the climate chamber, the calibration setup can experience an error of more than 20 % of full range. To minimize this error, we propose an optimized dual cascaded chamber calibration setup design and verify its thermal performance under the same environmental setup. The results show that the proposed design reduces the error, due to thermal gradient, down to 1.8 % of full range. In conclusion it is also discussed that the proposed design reduces error sources related to its mechanical complexity. Future work is proposed on the design and implementation of the optimized design.