Vaisala Oy

Nokia Corporation

Valtion Teknillinen Tutkimuskeskus

Vti Hamlin Oy

Altti Torkkeli

Ari Lehto

Martti Blomberg

Stefan Lindblad

Markku Orpana

Simo Tammela

Yrjo Koskinen

This invention relates to a differential pressure sensor, one embodiment of which is a microphone. The differential pressure sensor comprises: a flexible membrane () made of conductive material, which membrane forms a first electrode of the differential pressure sensor, and a perforated plate () made of conductive material, which plate is essentially more rigid than said membrane (), which plate is arranged at a distance from the membrane, and which plate forms a second electrode of the differential pressure sensor. In order to provide a differential pressure sensor with as good properties as possible, the differential pressure sensor comprises a substrate (), a cavity () extending through the substrate, the walls of which cavity are formed of said substrate (). The membrane () is closely connected to the walls of the cavity (), whereby the membrane forms a dense wall in said cavity, and said perforated plate () has been attached to the substrate with an insulating layer ().

Method of manufacturing a membrane sensor

The invention is related to an electrically modulatable thermal radiant source with a multilayer structure. The radiant source includes a substrate, a first insulating layer formed onto the substrate, a radiant surface layer formed onto the first insulating layer, a second insulating layer formed on the radiant surface layer, a first metallization (incandescent filament) layer formed on the second insulating layer, a third insulating layer formed on the first metallization layer, and a second metallization layer for contacting formed on the third insulating layer. According to the invention, very thin incandescent filaments are formed from the first metallization layer and surrounded by the other elements of the multilayer structure as a uniform, planar plate.

Electrically modulatable thermal radiant source with specific filament

A miniaturized spectrometer for gas concentration measurement includes a radiation source for admitting electromagnetic radiation onto the gas to be measured, a detector for detecting the radiation transmitted through or emitted from the gas, an electrically tunable Fabry-Perot interferometer placed in the path of the radiation prior to the detector, control electronics circuitry for controlling the radiation source, the interferometer and the detector. The radiation source, the detector, the interferometer and the control electronics are integrated in a miniaturized fashion onto a common, planar substrate and the radiation source is an electrically modulatable micromechanically manufactured thermal radiation emitter.

Miniaturized fabry-perot spectrometer for optical analysis

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.

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Espoo, Finland

Altti Torkkeli