Prototype Gages to Measure Plate Spacing in Flat Fuel-Plate Subassemblies

Abstract

The feasibility of two types of gages for measuring the plate separation in flat fuel-plate subassemblies was investigated with experimental model gages. One gage is based on a four-arm strain-gage bridge mounted on a flexible berylliumcopper beam. The deflection of the sensing beam as the gage traverses the channel is continuously recorded by a strain-gage analyzer. The second gage is a liquid-filled system consisting of a small flat pluager-and-cylinder arrangement. .4 rubber diaphragm between the piston and the cylinder serves as the seal. .4s the element is inserted in the space hettveen the plates, the piston is forced into the cylinder. The liquid, distilled water, thus displaced expands an external bellows. The variable expansion during a scan is measured by a differential transformer and recorded. The recorded output from either gage is directly proportional to the actual channel spacing and is reproducible to within 0.001 in. The general performances of the tno gages are equivalent except that an error of about 0.001 in. is introduced into the calibration of the hydraulic gage for each 3 F change in ambient temperature. The strain-gage-type gage is temperature compensated.