HIGH ACCURACY FIELD RESISTANCE MEASUREMENTS

THIS PHASE I EFFORT WILL ENDEAVOR TO DEVELOP THE DESIGN OF A HAND HELD, BATTERY OPERATED INSTRUMENT CAPABLE OF NUMERICALLY DISPLAYING HIGHLY ACCURATE RESISTANCE AND TEMPERATURE READINGS. A DIGITAL RATHER THAN ANALOG APPROACH IS PROPOSED. AN INTERNAL STABILIZATION SCHEME IS USED TO ISOLATE SENSITIVE COMPONENTS FROM THE ACCURACY DEGRADING EFFECTS OF THE OPERATING AMBIENT TEMPERATURE RANGE (-35 TO +45 DEG C). ANALYSES CONTAINED HEREIN INDICATE THAT RESISTANCE MEASUREMENT ACCURACY OF 40 PPM IS ACHIEVABLE AND THAT THE INTERNAL MICROPROCESSOR IS CAPABLE OF CONVERTING THERMISTOR READINGS TO TEMPERATURE READINGS WITH ACCURACY OF 0.001 DEG C. TOTAL ENERGY REQUIREMENTS ARE ALSO DISCUSSED AND METHODS OF REDUCING BATTERY SIZE AND WEIGHT ARE PROPOSED. SPECIFIC ELECTRONIC COMPONENTS ARE IDENTIFIED WHICH WILL MOST LIKELY BE USED IN PHASE I DEMONSTRATION HARDWARE.