This ultrasonic sensor has been developed and designed with the collaboration of one of the most wellknown research team, HZDR (Dresden Germany), who patented this new design and concept of wave guide. Manufactured under license, it is intended to be used with our DOP ultrasonic velocimeter for the measurement of velocity profiles in high temperature liquid metal. It combines a special ultrasonic wave guide attached to a specific ultrasonic transducer. This sensor allows to coupled ultrasonic energy inside a melt up to 600 degrees Celsius.