An ultrasonic calibration system for the University of New Hampshire Center for Ocean Engineering

A state-of-the-art ultrasonic transducer calibration system has been developed for use in the 40'/spl times/60'/spl times/20' deep tank at the University of New Hampshire, Center for Ocean Engineering (UNH/COE). The system has two major sub-systems, the mechanical hardware for handling the transducer under test; and the electronics for system control, and data acquisition and processing. The mechanical system is designed to be positioned anywhere in the tank, to be easily operated, to be capable of handling transducers up to 500 lb., and to be easily disassembled and moved to an out-door facility if necessary. The system can rotate transducers /sup +///sub -/45/spl deg/ in the vertical plane and 370/spl deg/ in the horizontal plane with a resolution of 0.10/spl deg/. The electronic system has two functions. One is to control the mechanical position of the transducer. The second is to acquire the required electro-acoustical data necessary to characterize the transducer. Transducers are characterized by their beam pattern, their electrical impedance, admittance, and receiving and transmitting voltage responses. Initial testing of the system has verified that it meets the design specifications. This system is housed at the University of New Hampshire, Center for Ocean Engineering and has enhanced the capabilities of Airmar Technology to calibrate and test its products, and has enhanced the capabilities of UNH/COE to educate students.