Strain sensitivity of pressure transducers in a dynamic environment

Abstract

Strain error in pressure measurements is recognized as a trouble source, but seldom Is it the major source of error in measurement. In experiments at the USERDA*s Nevada Test Site, it has been necessary to obtain dynamic pressure data from inside pipes which are subject to an initial tensile stress of about one-half yield which changes rapidly to failure in a compressive mode.Static and dynamic data show that representative pressure trans ducers are subject to strain error and that the error is not only a function of stress in the mounting, but is also dependent on the rotational position of the transducer (about its own axis) as it is ported into the pipe.Schemes for decoupling the transducer from the pipe without seriously decreasing the burst capability of the installation have been investigated.A mounting using an annular cut-out around the transducer barrel has been devised which significantly decreases strain error and has little effect on the installation integrity or the response to dynamic gas pressure.