Abstract: In order to cover a large measuring range extending from about 10.sup.-6 mbar to about 10 bar, a simple, compact and economically producible pressure sensor (3) arranged in a protective tube (1) has, on a support plate (5), a ceramic membrane (6) which, together with the support plate (5), forms a capacitive measuring element for the determination of pressures between about 0.1 mbar and 10 bar, and two measuring wires (11, 12) which are arranged adjacent to the membrane (6) and constitute a Pirani measuring element with substantial compensation of the effect of the wall temperature, for the determination of pressures between about 10.sup.-6 mbar and 1 mbar. The membrane (6) is shielded from the radiation of the measuring wires (11, 12) by a protective ring (16).

Abstract: In order to reduce the number of thin-films necessary to construe an interference band-pass filter for exclusive transmission of light in the UVA range the filter edge towards smaller wavelengths in the spectral characteristic is realized by the absorption edge of the material of one of the thin-films of a thin-film interference filter which filter produces the band-pass filter edge directed towards higher wavelengths.