Abstract: An electrically conductive polymeric housing or enclosure for process control equipment. The enclosure comprises a moldable thermoplastic polymer and carbon nanotubes. The carbon nanotubes are generally uniformly dispersed within said moldable thermoplastic polymer, such that the surface resistivity of the housing is less than 109 Ohms for Level 1 compliance.

Abstract: An electro-acoustic transducer is manufactured by forming a transducer assembly at least one piezoelectric element, electrodes contacting the element, and acoustic loading blocks, and applying successive superposed mouldings of material of differing acoustic properties around said transducer assembly to form the transducer, while maintaining electrical coupling between the transducer assembly and the exterior of the transducer, the mouldings providing at least one acoustic matching layer covering a radiating surface of the transducer assembly, a casing surrounding the remainder of the transducer assembly, at least one layer of acoustic isolating material between the casing and the transducer assembly. The successive layers may either be moulded in situ, or moulded separately and then assembled.