Borehole survey head - with acoustic transmitters mounted on mechanical low pass filter body

摘要

The body is based on discrete masses of steel W or U, joined elastically by the walls of a hollow cylinder or a pair of half shells of steel or Ti to which their ends are hard soldered or welded. They lie transverse to one diametral plane and rows of slots, perpendicular to the axis, are arranged in pairs in opposing offset quadrants the mass ends being sepd. axially by those of one pair of rows, whilst they lie between the ends of the other pair. Cross talk between send and receive transducers is prevented.