Abstract: A ball-and-socket joint is protected in sealed state by a boot firmly secured at its outer end to the ball stud of the ball and at its inner end to the joint assembly by a clamping ring made of an elastic material in the form of a coil wound spirally with rectangular-section winding turns thereof lying adjacently side-by-side in the plane of the clamping ring. The spirally-coiled construction, in contrast to a helically-coiled construction, of the clamping ring permits it to be expanded greatly at the time of its fitting in the boot groove for assembly with little permanent deformation, whereby a great clamping force is obtainable.

Abstract: An analysis system for a scanning electron microscope having a backscattered electron detector. The output of the detector is amplified, processed by an analogue to digital converter, multi-channel analyser, and digital conversion and processing circuit to generate a signal indicative of the atomic number factor of the specimen. Calculation of stoichiometric valence combinations of non-elemental specimens is also disclosed. A calibration device is also disclosed.