Surface effect ship air cavity pressure gages

Attempts were made to extend the design of an existing waterproof, high frequency, foil strain gaged, flush diaphragm, 10 psi pressure gage to the 1 psi range. Three diaphragm configurations were investigated: uniform thickness, tapered thickness, and cantilever supported. Design equations, for constructing these three types of diaphragms are given. From information derived from these equations, promising candidate pressure gages were built: uniform thickness diaphragm gages made of various plastic materials, and a cantilever supported diaphragm gage with membrane coverings of two different thickness. Also one gage was built using a foil strain gage itself as the diaphragm. The results of the static calibrations and frequency response measurements are given for these gages. One experimental cantilever supported diaphragm gage looks promising for further development. Suggestions for improving its performance are given.