DEVELOPMENT OF A PORTABLE ICE-MEASURING INSTRUMENT

THE HEAD PORTION OF THE PROPOSED ICE-MEASURING INSTRUMENT, WHEN SITTING ON THE ICE WILL DISPLAY A BRIM, ABOUT 7 INCHES ACROSS, WITH A SMALLER CONSOLE AT THE TOP, WILL HOLD FOUR TRANSDUCERS ARRANGED AT THE CORNERS OF A SQUARE, IN CONTACT WITH THE ICE SURFACE. THE CONSOLE WILL CONTAIN THE NECESSARY DRIVING, RECEIVING, AND COMPUTING CIRCUITRY AND A BATTERY. A HAND-HELD CONTROL AND DISPLAY UNIT, CONNECTED WITH THE MAIN UNIT THROUGH A RETRACTABLE CORD, WILL PERMIT THE OPERATOR FREEDOM OF STANDING AT A SHORT DISTANCE FROM THE HEAD. THE APPROACH INVOLVES TIMING OF THE TRAVEL OF ACOUSTIC PULSES FIRST GENERATED, THEN DETECTED AT THE ICE SURFACE AFTER BEING REFLECTED AT THE ICE/WATER INTERFACE. EQUATIONS HAVE BEEN DERIVED TO MAKE THE MEASUREMENT INDEPENDENT OF THE ACOUSTIC VELOCITY IN ICE AND CLOCK FREQUENCY. WAYS ARE PROPOSED OF AVOIDING DETECTION OF REFLECTED ACOUSTIC WAVES ON AIR BABBLES. THE INSTRUMENT PROVIDES SEVERAL MODES OF OPERATION, WHICH CAN USE CORRELATION BETWEEN MEASUREMENTS BY DIFFERENT SETS OF TRANSDUCERS TO OFFER A RELIABLE READING OF THE ICE THICKNESS. AS A BY-PRODUCT, THE INSTRUMENT MAY ALSO PROVIDE INFORMATION AS TO THE ICE DENSITY. IN PHASE I THE ELECTRONIC CIRCUIT, WHICH EMPLOYS A CALCULATOR CHIP, WILL BE BUILT AND BE USED IN ACTUAL MEASUREMENTS OF THICKNESS OF BLOCKS OF ICE OF VARIOUS DENSITIES AND WITH SIMULATED AIR BUBBLES. THE PROPOSED EQUIPMENT CAN HAVE COMMERCIAL APPLICATIONS, SUCH AS MEASURING THE ICE THICKNESS ON LAKES WHERE CHILDREN SKATE. VERIFICATION OF THE VALIDITY AND IMPLEMENTATION OF THE PROPOSED CONCEPTS CAN FURTHER THE ART OF NON-INVASIVE MEASUREMENT OF THICKNESSES OF MATERIALS BOTH SOLID AND FLUID.