Listening device for localizing underground water leakages

Claim 1

A listening device for pinpointing undergound water leakage sounds, and which includes an elongated rod with a handle on one end for manual positioning of the listening device, and which includes an acoustic pick-up means, on the other end of the rod, which is connected to an amplifier-receiver that receives the leakage sounds from the pick-up means and visual leakage signals may be seen on a level meter on the amplifier-receiver, and the leakage sounds may be heard through head-phones connected to the amplifier-receiver, characterized in that: (a) the acoustic pick-up means comprises a ceramic audio tone transducer; (b) the ceramic audio tone transducer comprises a brass diaphragm which is bonded to a metallized piezo-ceramic wafer by a conductive bonding agent; (c) the brass diaphragm and metallized piezo-ceramic wafers are each circular in plan view, with the brass diaphragm having a larger diameter; (d) a threaded attachment stud is directly attached to the brass diaphragm for attaching the acoustic pick-up means to said other end of said elongated rod; and, (e) the assembly of the brass diaphragm and metallized piezo-ceramic wafer is potted in a waterproof elastomeric material.