Homogeneous Vessels as Active Elements for Measuring Pressure

Abstract

This work investigates an approach to pressure sensor design in which a homogeneous vessel is used as the active element to sense pressure. The goal of this project was to synthesize a standard model for the design and development of a pressure sensor predicated on pressure vessel methodologies. Four prototypes were constructed, each implementing the experimental design using a different material and dimensions. A specialized testing apparatus was built to establish a controllable volume to which multiple devices can be connected and tested simultaneously. The data collection and measurement interface is also built into the testing apparatus.

The four prototypes with dissimilar geometries and materials are tested at room temperature for their repeatability in response to pressure and its transduction to voltage. When subjected to controlled pressures of up to 80 psi, strong agreement was observed between the prototypes under test and the actual pressure in the control volume; the physical design was validated for all four devices.

Uncertainty analysis was used to test for failure of the derived theoretical model to predict pressure with the measured voltage from the prototypes. Error limits established by the propagation of uncertainties were not exceeded by the model, and they were not rejected.