Ultrasonic thickness measuring system

Abstract

Abstract ULTRASONIC THICKNESS MEASURING SYSTEM IN WHICH BURSTS OF ULTRASONIC ENERGY ARE TRANSMITTED INTO A FRONT SURFACE OF A PART WITH RECEIVED SIGNALS BEING DEVELOPED FROM REFLECTIONS FROM THE BACK SURFACE OF A PART, THE TIME INTERVAL BETWEEN A TRANSMITTED BURST AND A CORRESPONDING RECEIVED SIGNAL BEING MEASURED ELECTRONICALLY, PREFERABLY BY DIGITAL MEANS. AN IMPORTANT FEATURE IS IN THE PROVISION OF MEANS FOR AUTOMATICALLY CONTROLLING THE GAIN OF AN AMPLIFIER TO DEVELOP AMPLIFIED RECEIVED SIGNALS OF CONSTANT AMPLITUDE IN RESPONSE TO BACK REFLECTIONS OF VARYING AMPLITUDE WHICH PERMITS MUCH MORE ACCURATE MEASUREMENT. ANOTHER IMPORTANT FEATURE IS IN THE PROVISION OF AN INTEGRATOR FOR PRODUCING A CONTROL SIGNAL HAVING A DURATION DIRECTLY PROPORTIONAL TO AND AT LEAST SEVERAL TIMES LARGER THAN THE TIME INTERVAL BETWEEN A BURST AND THE CORRESPONDING REFLECTION, WHICH PERMITS MUCH MORE ACCURATE MEASUREMENT WITH A PRACTICAL DESIGN OF TIME MEASURING MEANS. THE INTEGRATOR MAY COMPRISE A MEANS FOR CHARGING A CAPACITOR AT A UNIFORM RATE DURING THE TIME INTERVAL BETWEEN A BURST AND THE CORRESPONDING REFLECTION AND FOR DISCHARGING THE CAPACITOR AT A UNIFORM BUT MUCH SLOWER RATE. A FURTHER FEATURE RELATES TO THE OPERATION OF THE TIME INTERVAL MEASURING MEANS PERIODICALLY AT A SLOW RATE SUCH THAT THE MAXIMUM DURATION OF THE TIME INTERVAL MEASURED IS A SMALL FRACTION OF THE TIME BETWEEN OPERATIONS OF THE MEASURING MEANS, WHICH CONSERVES POWER AND IS OTHERWISE ADVANTAGEOUS.

Inventors

• 👤 George L Kummer Jr
• 👤 Ronald A Straw
• 👤 John A Wendt

Bibliographic Details