On the additional error of a nonlinear hydraulic measuring circuit with pressure pulsations at the inlet

Abstract

In power plant and test equipment control systems pressure sensors are often connected by pressure transmission lines for conditions of high temperatures and vibrations. In the presence of pressure pulsations in the monitored object, a restrictor is installed at the pressure transducer inlet. Restrictors serially produced for pressure transducers have a nonlinear flow-drop characteristic which leads to the additional measurement error of the medium or slowly changing component of the pulsating pressure. This distortion can significantly exceed the error of the transducer itself. The results of theoretical and experimental studies of the additional error depending on the parameters of the measurement circuit and pressure pulsations (amplitude, frequency, spectrum and phase shift between components) are presented. Recommendations on the choice of damper parameters for which the additional error can be neglected are given. The methodology developed by the authors can be used to create measurement circuit for an average or slowly changing component of the pulsating pressure measurement in power plant monitored measurement and control systems.