Abstract: In a clamping unit, particularly in a chuck with exchangeable jaws, one terminal clamping position is reached during opening when the clamping jaws approach the limit of stability. The other end position is reached during closing when the jaws approach the point where they cannot be moved any further. However, both end positions must be so far removed from the rest position or the stop position that a residual clamping stroke remains which insures safe clamping even then in the terminal clamping positions. The terminal clamping positions are different for chucks of varying sizes, and so are the clamping strokes. To adjust the end positions as well as for determining the attainment of these end positions, an apparatus is provided comprising a transmitter device and a sensor device which reacts to approach or contact. Spacing is changeable with the adjustment of the clamping jaws.

Abstract: In a method and apparatus for measuring the concentration of a fluid depending on the dielectric constant of the fluid, electric oscillations are supplied from a source through an impedance matching link to an antenna placed in the liquid within the confines of a Faraday cage, and the electric power reflected from the antenna towards the source is measured to determine deviations from ideal matching resulting from changes of the dielectric constant of the fluid. In an important embodiment, the measurement is used for the automatic programmed control of the supply of syrup in a sugar crystallization process in accordance with a predetermined program.