PROPERTIES OF ELECTROKINETIC TRANSDUCERS AND FACTORS DETERMINING THEIR SUITABILITY IN VARIOUS APPLICATIONS
Abstract
Electrokinetic transducers are defined as devices which employ the Helmholtz double-layer at a solid-liquid interface as a means of intraconverting mechanical and electrical energy. Devices are considered in which a liquid is forced through a microporous plug to produce a streaming potential which is measured to determine the unknown pressure or used to perform some usefule function. A theoretical study indicated that the sensitivity of such a device is proportional to the electric movement of the double layer and the porosity factor, and inversely proportional to the over-all conductivity of the liquid- filled plug and the viscosity of the liquid. Mechanical design considerations determine the LF limit of operation. With a proper choice of inert materials, transducers of this type can be produced which achieve a constant stable sensitivity. The sensitivity of a typical electrokinetic transducer is about 45 db below that of an ordinary air microphone, and 40 db above that of typical piezoelectric devices which are used for shock-wave and blast measurements. The principal advantage of the electrokinetic transducer over the piezoelectric is that the impedance is resistive and independent of frequency. This advantage is most significant in the 0.01- to 1000-c range.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1952
- Accession Number
- AD0008015
Entities
People
- E. V. Hardway Jr.