TORSIONAL SENSOR FOR MONITORING LIQUID LEVEL AND DENSITY

THE PROBLEM OF ACCURATELY MEASURING DENSITY AND LEVEL OF SALT-BEARING RADIOACTIVE LIQUIDS IS COMPLICATED BY INTERFERING VARIABLES SUCH AS TEMPERATURE PROFILE, LIQUID COMPOSITION, SENSOR FOULING BY SALT BUILDUP, THE NUCLEAR ENVIRONMENT, AND THE SIZE, ACCESS AND MAINTENANCE CONSTRAINTS IMPOSED BY THE EXISTING LARGE BURIED STORAGE TANKS. TO SOLVE THIS PROBLEM, WE PROPOSE THE USE OF ULTRASONIC TORSIONAL WAVES IN SENSORS HAVING TWO SPECIAL CROSS SECTIONS. THE SENSOR OF NONCIRCULAR CROSS SECTION RESPONDS TO DENSITY RHO WHEN ORIENTED HORIZONTALLY, AND TO THE PRODUCT OF DENSITY AND HEIGHT, RHOH, WHEN VERTICAL. THE SENSOR OF CIRCULAR CROSS SECTION RESPONDS TO THE PRODUCT OF DENSITY AND VISCOSITY, RHOETA. THE "VISCOSITY" SENSOR IS INCLUDED TO MONITOR SALT BUILDUP AND COMPENSATE FOR BUILDUP IF IT OCCURS. SENSOR MATERIAL, SURFACE PREPARATION AND POSSIBLY VIBRATORY MEANS SHALL BE SELECTED TO DISCOURAGE SALT BUILDUP. TEMPERATURE COMPENSATION IS TO BE ACCOMPLISHED BY TIMING EXTENSIONAL WAVES IN THE SAME SENSORS THAT, WHEN TORSIONALLY EXCITED, RESPOND TO RHO, ETA,OR H.