AIR MASS MEASUREMENT INDICATOR FOR PORTABLE LIQUID AIR DEWAR

A MEASURING SYSTEM CAPABLE OF REAL-TIME DISPLAY OF THE AMOUNT OF AIR REMAINING IN A LIQUID AIR RESPIRATOR STORAGE DEWAR, REGARDLESS OF DEWAR ORIENTATION OR USE RATE, WILL SIGNIFICANTLY ENHANCE UTILIZATION OF THE RESPIRATOR AND REDUCE UNNECESSARY DOWN TIME FOR TANK RECHARGING. THE PROPOSED MASS MEASURING SYSTEM CONSISTS OF FOUR INSTRUMENTEDSUPPORTS PROVIDING SIGNALS TO A MICROPROCESSOR WHICH CONVERTS THE SIGNALS TO FORCES AND MOMENTS AND RESOLVES THESE INTO THE TOTAL GRAVITY FORCE ON THE TANK. KNOWING THEEMPTY TANK WEIGHT, THE WEIGHT OF ONBOARD AIR CAN BE DETERMINED, AN ADDITIONAL PRESSURE AND TEMPERATURE MEASUREMENT WILL ALLOW THE DETERMINATION OF THE LIQUID AND VAPOR MASS. LOW FRICTION MATERIALS SUCH AS TEFLON AND ANTIFRICTION BEARINGS WILL BE INVESTIGATED TO MINIMIZE FRICTION BETWEEN THE INSTRUMENTED SUPPORTS AND SUPPORTING STRUCTURE TO IMPROVE THE SENSITIVITY OF THE MASS MEASURING SYSTEM. DESIGN FEASIBILITY WILL BE DETERMINED BY DEVLOPING A CONCEPTUAL DESIGN OF THE PROPOSED CONCEPT. CONCEPTS FOR THE INSTRUMENTED BEAMS WILL BE DEVELOPED, SOFTWARE TO CONVERT THE MEASUREMENTS TO WEIGHT OF GASEOUS AND LIQUID AIRWILL BE DEVELOPED, AND REQUIREMENTS FOR THE MICROPROCESSOR AND DIGITAL DISPLAY DEFINED. THIS INFORMATION WILL BE INTEGRATED TO PROVIDE AN OVERALL CONCEPTUAL DESIGN OF THE PROPOSED SYSTEM WITH SUPPORTING DATA TO DEMONSTRATE FEASIBILITY.