A New, Further Stabilized Strain Gage Type Low Pressure Engine Indicator, Development and Analysis 700499

A low-pressure indicator incorporating high stability, high sensitivity to the required pressure, and nonsensitivity to engine vibration has been developed. This new indicator employs a peripherally fixed strain-generating disk and a wavy cone type of diaphragm, which is insulated from the outer body by a silicone O-ring. The generated strain was detected by a strain gage that had high compensating performance for the temperature. Analytical study was made to get the optimum design for disk thickness, diameter, and additional vibrating mass. The combination of this analytical study and the development of several new devices made possible the incorporation of various innovations in this newly developed low-pressure indicator which was designed to obtain data that would augment present methods of engine analysis.