Abstract: The invention relates to an overpressure protector comprising a body portion (1) of single crystal silicon, a burst flow conduit (2) extending through the body portion (1), and a membrane (3) covering the burst flow conduit (2) and responding to a pressure difference. The membrane is a thin film (3), which is arranged to break when the pressure difference acting across it exceeds a predetermined value, and comprises a belt (6) whose electrical conductivity differs from that of the other material of the membrane. The belt is connected to means (9) for supplying electric current either for detecting breaking or the belt or for bursting the membrane (3) intentionally by means of heating effect of electric current.

Abstract: A single-channel gas concentration measurement method and apparatus. According to the method, a radiant source is employed to generate a measuring signal, the measuring signal is subsequently directed to a measurement object containing a gas mixture to be measured, the measuring signal is subsequently bandpass filtered using at least two passband wavelengths, and the filtered measuring signals are detected by a detector. According to the invention, the bandpass filtering step is implemented by a single electrostatically tunable, short-resonator Fabry-Perot interferometer.

Abstract: An electrically modulatable radiant source includes an essentially planar substrate, a well or hole formed in the substrate, and at least one incandescent filament attached to the substrate. The incandescent filament is aligned with the well or hole and is formed of a metallic compound which readily oxidizes at an operating temperature of the incandescent filament. An oxidation resistant film encapsulates the incandescent filament to prevent the filament from oxidizing. Furthermore, contact pads are formed on the substrate at both ends of the incandescent filament for feeding electric current to the incandescent filament.

Abstract: An electrostatically tunable Fabry-Perot interferometer produced by surface micromechanical techniques is used in optical material analysis as an optical sweeping filter in which the optical measurement wavelength is centered at a wavelength .lambda.. The Fabry-Perot interferometer based sensor structure comprises a body block, two essentially parallel mirrors bonded to the body block, of which mirrors at least one is partially transmitting and movable relative to the body block. The mirrors are spaced maximally by a few half-wavelengths, .lambda./2, from each other, and both of the mirror structures include integral electrode structures capable of effecting an electrostatic force between the mirror structures. The movable mirror structure is provided with structurally weakened regions surrounding the optical area of the mirror so as to facilitate keeping the optical area at a maximum degree of flatness.

Abstract: A radiant source including an essentially planar substrate having a well or hole formed therein. At least one incandescent filament is mounted to the substrate and aligned at the well or hole. Contact pads are formed onto the substrate, to both ends of the incandescent filament, and feed electric current to the incandescent filament. Furthermore, each incandescent filament is doped with phosphorus to an impurity concentration of at least 5.times.10.sup.19 atoms/cm.sup.3.