Abstract: An acoustic detector that includes active noise cancellation is presented. An acoustic detector converts sound waves, which include sound waves of interest as well as noise, to an electronic signal. An operator listens for a characteristic sound, for example the sound characteristic of fluid leaking from a pipe, as she varies the position of the transducer. At least one other acoustic detector is positioned in order to monitor noise. The electronic signal from the noise monitoring acoustic detector and the electronic signal from the acoustic detector are combined in a processor in order to cancel the noise. In some embodiments, the operator may adjust a cancellation band so that some frequencies are not cancelled. For example, the operator may adjust the cancellation band so that a co-worker's voice may be heard.

Abstract: A heat-recoverable soldering device for soldering electrical conductors comprising a heat-recoverable sleeve and a quantity of solder is provided with a deformable retaining member which retains the conductors in the desired alignment when deformed.

Abstract: This invention relates to heat-shrinkable devices for forming solder connections between two bodies such as electrical conductors or pipes. The devices each comprise a hollow, heat-shrinkable sleeve having at least one aperture and containing first and second solder inserts. The solder inserts are located adjacent to each other and the second insert responds to heat applied to the device more slowly than the first insert. Usually the second insert has a higher melting point than the first insert. When the device is installed the first solder insert melts but is prevented from flowing out of the aperture in the device by the second insert. Also flow of the fused first solder insert onto the second solder insert causes the second insert to melt with less heat being applied to the device than would be needed if only the second, higher melting point solder insert were present in the device.