Abstract: A damping device for use with acoustic information generation machines for isolating a generation portion of the generation device from contamination by extraneous acoustic emissions. A metal isolation piece consisting of a shape-memory alloy is disposed between an extraneous noise source and the generation portion of the device. Acoustic information generation devices in accordance with the present invention include phonograph record playing devices and testing devices for recording acoustic signals generated upon stressing a test piece. Thus, the present invention provides improved phonograph record playing devices and an improved testing device.

Abstract: Strain gauges are attached to a drill pipe which is inserted into a drill pipe string to be used in a well. The strain gauges are connected to an electrical circuit containing devices for digitizing the electrical signals generated by the strain gauges in response to the detection of strain and for recording and retaining the digitized signals until the drill pipe string is extracted from the well. The electrical circuit provides a communication path through which the stored digitized data is transferred to an external device when the drill pipe string is extracted from the well.