Response of Pneumatic Pressure-Measurement Systems to a Step Input in the Free Molecule, Transition, and Continum Flow Regimes

摘要

A simplified analysis of the response of pressure-sensing devices and their interconnecting tubing is presented. The results are conveniently presented in the form of time equations, with a fraction of the applied step (usually 63.2%) attained at the sensor as the variable. A single algebraic equation adequately predicts the response of pressure-measuring systems in the free molecule, transition, and continuum flow regimes. Two very simple algebraic equations may be used to predict time response in the free molecule and continuum flow regimes. The formulas are limited where viscous flow occurs, and they are not restricted for free molecule flow. All of the formulas are suitable for field engineering applications. The literature is synthesized by comparing the results from selected references with those of the analysis. Factors influencing transient pressure measurements are reviewed. (Author)