Vaisala Oy

Ingmar Stuns

Heikki Turtiainen

Simo Tammela

Jorma Ponkala

Veijo Antikainen

Osmo Reittu

The invention concerns an electrical impedance detector for measurement of physical quantities, in particular of temperature or humidity, as well as a process for manufacture of the detectors. The impedance detector is composed of pieces cut off from a continuous detector filament (20). The detector filament (20) comprises an electrically conductive pair of electrode wires (10a,10b) or an equivalent assembly of electrode wires, on/between which there is an active material (11) whose impedance properties are a function of the physical quantity to be measured. The different electrode wires (10a,10b) of the detector filament (20) in the pieces of detector filament (20) have been cut off at different points (41a,41b), compared with one another, so that the impedance (CM) to be measured will be formed in the area (CV) between the cut-off points (41a,41b) of the electrode wires (10a,10b). As the starting material of the active material layer (11') in the detector, a glass paste (11P) is used, through which the pair of electrode wires (10a,10b) is drawn through the drying oven (34) onto the receiving frame (35). The stage of crystallization of the active material layer takes place in a separate heat-treatment stage which takes place after the winding stage.

Method of manufacturing an impedance detector

Electrical impedance detector for measurement of physical quantifies, in particular of temperature or humidity. The detector comprises conductor electrodes (10a, 10b; 10A,10W), between which the electrical impedance (C.sub.M) that represents the physical quantity to be measured is measured. Between the conductor electrodes (10a, 10b;10A, 10W) there is an active material (11;11P) whose impedance properties are a function of the physical quantity to be measured. The detector is composed of pieces cut-off out of a continuous detector filament (20; 20H;20K), which detector filament (20;20H;20K) comprises a conductive electrode wire or an assembly of electrode wires (10a, 10b; 10A, 10W), on/between which there is an active material (11;11P) whose impedance properties are a function of the physical quantity to be measured. Further, a novel process is described for the manufacture of said detectors.

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Ingmar Stuns