Acoustic borehole logging tool

Claim 1

Using a borehole logging tool having an elongated borehole tool for inserting into a fluid-filled borehole, at least one transducer located in said tool for directionally transmitting bursts of acoustic energy into the formations surrounding said borehole and for receiving said acoustic energy being reflected back to said borehole tool as an indication of the condition of said surrounding formations and of the borehole wall, a compartment in said tool within which said transducer is mounted, a coupling liquid filling said compartment, and a window in the periphery of said compartment, a method for determining the thickness of the particular material being utilized for said window, comprising the steps of: (a) measuring the acoustic energy signal transmission through said window for a plurality of differing window thicknesses, (b) measuring the noise transmission through said window for each of said plurality of differing window thicknesses, (c) determining the ratio of the signal-to-noise transmissions from steps (a) and (b) and (d) selecting the material thickness for said window that yields the largest signal-to-noise ratio.