Experience in the Use of the Gibson Method of Water Measurement for Efficiency Tests of Hydraulic Turbines

Abstract

The purpose of this paper is to examine the records of experience, for 35 years from 1920 to 1955, in the use of the Gibson Method and Apparatus, for measuring the flow of water as applied in field efficiency tests of turbines in hydro-electric power plants. Diagrams based on tables of maximum efficiencies of comparable units, from a total of 310 tests are presented. A few unusual experiences are cited and described. A comprehensive discussion of the accuracy of the method is given; with particular reference to the critical analyses of Francis Salgat and the late Dieter Thoma and others and to the precision which can be expected in determining the various factors required for measuring water quantities by this method. Four appendixes give: (1) A brief description of the Gibson Method and Apparatus; (2) some slight revisions of the author’s original paper published by ASME in 1923; (3) a numerical example of the delineation and computation of a differential pressure-time diagram; and (4) a partial Bibliography with notes.