Abstract: A tube arrangement has a first partial tube and a second partial tube, and one fine adjustment arrangement for coaxially displacing the partial tubes with respect to one another. The partial tubes, an aperture ring with a small aperture opening, a beta radiator point source and a GM-counter are coaxially arranged. The partial tubes are connected each with one or two of the following: an aperture ring, the beta radiator point source, and the GM-counter. A blocking means blocks the fine adjustment arrangement. One of the partial tubes is connected galvanically conducting with the GM-counter anode and the other partial tubes are connected galvanically conducting with the GM-counter cathode.

Abstract: An electrolyte chamber has an opening on the side facing the foil to be measured for letting the electrolyte through to the foil, a hollow cathode in the chamber, a supply line connected to the chamber through the hollow cathode for supplying the electrolyte to the chamber, and a negative pressure flow-off line connected to the chamber located at a distance from the mouth of the supply line. A negative pressure generator is connected to the flow-off line through a separator vessel which has a level switch which shuts off the generator when the electrolyte reaches a predetermined level. The supply line is connected to a supply vessel containing the electrolyte and runs continuously into the liquid volume in the vessel. The vessel has a connection to the atmosphere.

Abstract: The apparatus measures the thickness of thin layers on strips and wires which are moved relative to the apparatus. The apparatus is stationary and includes one or more beta emitters directed towards the layer and spatially arranges relative to the longitudinal axis of a beta radiation detector or counting tube which is arranged to the rear of the beta emitter for counting the backscattered beta radiation, and a guide for the strip or wire at a specified distance from the beta emitter. The ratio of the characteristic cross-sectional dimension (D) of the window of the beta radiation detector to the intersecting surface diameter (d) of the intersecting surface layer/intensity distribution curve of the beta emitter, being expressed as D/d=15 . . . 2; with the distance between the layer and the beta radiation emitter being in the plateau region of the curve of the counting rate/distance characteristic obtained by the above feature.