Abstract: The system and the method of the present invention differ from the prior art in that radii of curvature of any length of spherical and cylindrical test surfaces can be optically measured, with only a supplementary dual-focus lens being required in addition to an interferometer or an autocollimator. The supplementary dual-focus lens has a first focal plane, into which the surface vertex of the test surface is positioned, which establishes the cat's eye position (P(cat)), and a second focal plane into which the center of curvature of the test surface is moved, which establishes the autocollimation position (P(aut)) for the test surface. The radius of curvature of the test surface is determined from the distance between the focal planes (D(foc)) and the path of movement which can be reduced to zero.

Abstract: The system and the method of the present invention differ from the prior art in that radii of curvature of any length of spherical and cylindrical test surfaces can be optically measured, with only a supplementary dual-focus lens being required in addition to an interferometer or an autocollimator. The supplementary dual-focus lens has a first focal plane, into which the surface vertex of the test surface is positioned, which establishes the cat's eye position (P(cat)), and a second focal plane into which the center of curvature of the test surface is moved, which establishes the autocollimation position (P(aut)) for the test surface. The radius of curvature of the test surface is determined from the distance between the focal planes (D(foc)) and the path of movement which can be reduced to zero.

Abstract: The invention relates to a label comprising a tab (2). The inventive label is characterized in that in the area of the tab (2) the adhesive coating (3) is imprinted with an intumescence coating, i.e., a layer (4) from a foamable material, thereby reversing the adhesive effect of the adhesive coating (3) on the support (5) in the area of the tab (2). In principle, the foamable. layer (4) does not necessarily have to be provided on the adhesive coating (3). It can also be provided directly on the bottom face of the plastic film layer (1). The layer (4) serving as the intumescent means is activated by heating it. Once the layer (4) has been activated, the area of the tab (2) is prominent to such an extent that it can be easily gripped in order to peel of the label from the support (4). Since the layer (4) cannot freely expand in the area adjoining the adhesive layer (3), this area is arched, i.e., the tab (2) stands out above the edge of the support (5), thereby making it easier to lift it off.

Abstract: The invention relates to a method for producing non-pilling polyester fibres, whereby polyethylene terephthalate is produced in the presence of organosilicon compounds of tetrahydrofurfuryl alcohol. Preferably, tetrakistetrahydrofurfuryloxysilane or tris[tetrahydrofuryloxy]methylsilane is used.

Abstract: The invention relates to a method for producing non-pilling polyester fibres, whereby polyethylene terephthalate is produced in the presence of organosilicon compounds of tetrahydrofurfuryl alcohol. Preferably, tetrakistetrahydrofurfuryloxysilane or tris[tetrahydrofuryloxy]methylsilane is used.