Abstract: A measuring arrangement for radiometric density-or fill level measurement of a medium in a measuring tube in the field of automation technology. The measuring arrangement is composed of a radioactive radiation source, a detector unit and a clamping apparatus for the radiation source as well as the detector unit. The invention is distinguished by features including that the clamping apparatus has blocking elements, which make the radiation cone of the radioactive radiation source between the measuring tube and the clamping apparatus laterally inaccessible. In such case, the blocking elements are arranged in such a manner that the measuring arrangement is suitable for different diameters of the measuring tube, without the blocking elements losing their protective action.

Abstract: The invention relates to a measuring arrangement (1) for radiometric density- or fill level measurement of a medium in a measuring tube (2) in the field of automation technology. The measuring arrangement (1) is composed of a radioactive radiation source (3), a detector unit (4) and a clamping apparatus for the radiation source (3) as well as the detector unit (4). The invention is distinguished by features including that the clamping apparatus has blocking elements (7,8,9,10), which make the radiation cone (17) of the radioactive radiation source (3) between the measuring tube (2) and the clamping apparatus laterally inaccessible. In such case, the blocking elements (7,8,9,10) are arranged in such a manner that the measuring arrangement (1) is suitable for different diameters of the measuring tube (2), without the blocking elements (7,8,9,10) losing their protective action.

Abstract: A grease gun for lubricating machines, includes a housing having an inlet opening for receiving grease therethrough into the housing and an extrusion opening through which the grease is pushed out to a machine to be lubricated; a drive shaft rotatably mounted in the housing and having an outer surface with external threads thereon; a conveying piston mounted in the housing and partially surrounding the drive shaft, the conveying piston having internal threads for engaging with the threads on the drive shaft; a reversible drive motor rotating the drive shaft so as to cause the piston to move toward and away from the extrusion opening; and a seal associated with the conveying piston for sealing the inlet opening when the piston is moved toward the extrusion opening.

Abstract: A grease gun for lubricating machines, includes a housing having an inlet opening for receiving grease therethrough into the housing and an extrusion opening through which the grease is pushed out to a machine to be lubricated; a drive shaft rotatably mounted in the housing and having an outer surface with external threads thereon; a conveying piston mounted in the housing and partially surrounding the drive shaft, the conveying piston having internal threads for engaging with the threads on the drive shaft; a reversible drive motor rotating the drive shaft so as to cause the piston to move toward and away from the extrusion opening; and a seal associated with the conveying piston for sealing the inlet opening when the piston is moved toward the extrusion opening.

Abstract: A process for the preparation of perfluoroalkyl compounds which comprises reacting a perfluoroalkyl-trimethylsilane of the general formula (CH.sub.3).sub.3 Si-C.sub.n F.sub.2n+1 (I), wherein the group C.sub.n F.sub.2n+1 represents a perfluoroalkyl group having from 1 to 6 carbon atoms, with a carbonyl compound of the general formula F.sup.1 --CO--R.sup.2 (II), wherein R.sup.1 represents a hydrocarbon group or hydrogen and R.sup.2 represents a hydrocarbon group, a perfluoroalkyl group or a perfluoroaryl group, but wherein R.sup.1 and R.sup.2 together may also be part of an alicyclic ring system, in the presence of a salt-like fluoride--which is at least partially soluble in the reaction medium--as a catalyst to yield a silylether of the formula ##STR1## and isolating this compound or hydrolyzing it to yield an alcohol of the formula IV ##STR2## The invention also relates to pentafluoroethyl trimethylsilane (CH.sub.3).sub.3 Si--CF.sub.2 CF.sub.3 and a process for the preparation of this compound.

Abstract: 1-Arylalkoxy-tris(dialkylamino)phosphonium salts of the formula I ##STR1## wherein the substituents R.sup.1 to R.sup.5 are equal or different and represent hydrogen, alkyl having from 1 to 6 carbon atoms which may be perfluorinated, halogen, alkoxy or alkylthio, each having from 1 to 6 carbon atoms, Y represents hydrogen or a perfluoroalkyl group C.sub.n F.sub.2n+1 having from 1 to 6 carbon atoms, X represents bromine or iodine and "Alkyl" represents an alkyl group of 1 to 3 carbon atoms, at most 3, preferably at most 2, of the groups R.sup.1 to R.sup.5 having a meaning other than hydrogen and the alkyl, alkoxy and alkylthio substituents attached to the aromatic nucleus altogether containing preferably at most 6 carbon atoms, in particular at most 4 carbon atoms.