Vaisala Oy

Vaisala Ox

Jouko S Jalava

Ari Lehto

Heikki T Kuisma

Lars Stormbom

Pekka Belt

Heikki Mesia

Kalervo A Jappinen

Marja-Riitta Hakala

Disclosed herein is a humidity calibrator device including a base part sealed by plugs, and a replaceable humidity calibrator cartridge. The cartridge contains saturated vapor, saturated salt solution and salt crystals. The cartridge is sealed with a semipermeable membrane and an air-tight protective peel-off foil. The semipermeable membrane, which seals the part of the humidity calibrator cartridge entering the base part of the apparatus provides a separation of the compartment in the base of the apparatus and liquid containing space of the cartridge, allowing permeation of water vapor and preventing permeation of the liquid.

Field usable calibrator for humidity meters

This invention concerns a method for trimming a planar capacitor. According to the method, a laser emission is focused to an electrode of a capacitor formed on a substrate transparent to laser emission and including of an upper electrode, an insulation layer, and a lower electrode, in order to achieve a passivation effect on the electrode. The laser emission is focused according to the invention locally onto the lower electrode through the substrate in order to achieve a heating effect on the lower electrode, thereby oxidizing the electrode material so that the lower electrode is locally converted into an electrically nonconductive state while being protected by the substrate and the insulation layer. The trimming method in accordance with the invention is accurate and offers a stable capacitance value.

Method for trimming a planar capacitor

The present publication describes a capacitive humidity sensor and a method for the manufacture of same. The sensor comprises a substrate (1), first (5) and second bottom electrodes (4), which have been fitted close to each other on the substrate (1), an active layer (7), which fills the area between the first (5) and the second bottom electrodes (4) on the substrate (1) and extends to above the top face of the second electrode (4). According to the invention, the sensor further consists of structures (6) connected to the top face of the first electrode (5), made of a conductive material, and being beam-shaped with an upwardly widening section and being placed side by side, the said structures (6) limiting portions (7) of the active layer between themselves from two sides, and a narrow slot (26) being provided between the top faces of the said structures. Owing to its construction, the sensor is not sensitive to touching.

Capacitive humidity sensor and method for the manufacture of same

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Vantaa, Finland

Jouko S Jalava