MULTIDIRECTIONAL TURBULENCE PROBE DEVELOPMENT. PHASE I. UNIDIRECTIONAL TURBULENCE SENSOR DEVELOPMENT

Development of a unidirectional-turbulence probe was undertaken to investigate the feasibility of a small-diameter strain-gaged diaphragm-type pressure transducer and a self-adjusting depth compensation air reservoir for use in the follow-on development of a small (1/2-inch diameter) multidirectional-turbulence probe. A unidirectional probe was developed which is capable of monitoring water velocities over a range of 0.5 to 5 ft/sec in turbulence frequencies of 0 to over 100 Hertz and which will automatically operate in water up to 10-feet deep. Sealing inadequacies in both the air reservoir membrane and the pressure diaphragm permit moisture entry into the air volume covering the strain gages. This has given rise to balance drift and circuitry ground problems that have resulted in the placing of limitations on the water exposure and turbulence monitoring times for the unidirectional probe. These problems also suggested that the concepts cannot be immediately incorporated into a multidirectional probe design.