Asea Aktiebolag

Lars Sander

Torgny Brogardh

Christer Ovren

Carl E Solver

Olof Engstrom

Svante Forsberg

Anders Linge

Borje Erikmats

Thorbjorn Collin

Harry Goransson

In a means for detecting the wear of a current interrupting contact (4) there is used a light conductor (12) as a connecting link between the contact (4) and a detector (20) arranged at ground potential. The light conductor is inserted into an aperture (11) provided from the rear side of the contact, the bottom of said aperture being positioned at the level corresponding to a worn out contact. When the wear has grown so great that the light conductor (12) is exposed, the light or heat of the breaking arc will generate or interrupt a light signal, which via the light conductor is transmitted to the detector.

Means for detecting the contact wear of electrical switching devices

The present invention relates to an optical measuring device for measuring physical quantities, comprising a measuring transducer and an evaluating electronic unit, interconnected by a light-transmitting system and photo-optic devices for coupling in light from a light source to the system, and for coupling out light from the system to photo-detector devices in the electronic unit. The measuring device comprises a first element for polarizing the light from the light source and a second element for polarizing the light to the photo-detector devices, the difference in the direction of polarization between the two polarizing elements being chosen so that light reflections in the system in and adjacent to the evaluating electronic unit are substantially blocked from the photo-detector devices by the second polarizing element.

Optical measuring device with means for suppressing reflections

The invention relates to a fiber optic measuring device for measuring physical and chemical quantities. Sensors positioned in the ray path influence the spectral composition of the light in dependence on the quantity to be measured. The sensors are of a material with an absorption edge or one or more filters of interference type.

Fiber optic measuring device with compensation for reflections in the

The invention relates to a fiber optical measuring device for measuring physical and/or chemical parameters. The device comprises a transducer unit and an evaluating unit, connected via at least one light conductor. One or more light sources in the evaluating unit, via said at least one light conductor, illuminate one or more optical filters located in the transducer unit which filter(s) is (are) sensitive to the parameter being measured. An optical detector arrangement in the evaluating unit analyzes the light emanating from the transducer unit. The detector arrangement consists of one or more photo-detectors, arranged to sense the light emitted from the transducer unit after this light has been affected by at least one filter belonging to the detector arrangement. The spectral properties of the detector filter(s) are controlled so that the detector arrangement is able to measure the correlation between the spectra of the transducer and detector filters. The correlation values are used as a measure of the condition of the transducer filter and thus of the parameter(s) being measured.

Correlating fiber optical measuring device

The invention relates to a device for measuring current which traverses a light-emitting structure, the current passage thus causing emission of light. It is characterized in that the emitted light signal is adapted to be supplied to two photo-detectors having different sensitivity spectra and/or with at least one photo-detector being provided with an optical filter. The output signals of the photo-detectors are adapted to be supplied to a quotient forming member and/or a calculating member for obtaining a signal which is compensated for temperature variations in the light-emitting structure and other sources of error.

Current measuring apparatus using light-emitting devices

The invention relates to a fiber optical temperature measuring device of the pyrometer type, comprising a transducer section and an electronic section, which are mutually interconnected by at least one optical fiber. The electronic section includes at least one light source and the light therefrom is arranged to be emitted via the optical fiber to the transducer, and in the transducer at least part of the light is reflected back into the fiber and is conducted through the optical fiber together with an output measuring signal from the transducer to one or more detectors included in the electronic section.

Fiber optical temperature measurement devices

A fiber optical temperature measuring apparatus is based on the ability of certain materials to change color in dependence on changes in temperature. Visible or invisible light having at least two different wavelengths is supplied to the material and the light emanating from the material is detected for determining the changes in the absorption characteristic of the material at the emitted wavelengths by determining the quotient between the detected signals from the material.

Growing community of inventors

Vaster.ang.s, Sweden

Lars Sander