Electrochemical sensor element construction
AssigneeRobert Bosch GmbH
InventorHelmut Maurer
Life of this patent
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Abstract
To improve uniformity of heating of a sensor element carried on a plate-like carrier, in which electrodes are applied to one or both of the major surfaces of a carrier plate to form the sensor element, the heater element is constructed in form of a zig-zag or meander track surrounding the flat electrodes and positioned adjacent the edge portion of the carrier plate, so that, in a direction transverse to the major plane of the carrier plate, the heater element will be positioned closely adjacent the electrode, and prevent the formation of temperature gradients which might lead to fissures or breaks in the elements of the sensor construction.
Claims10
Electrochemical sensor construction adapted for positioning in a stream of combustion gases, having
- a plane carrier plate (10, 27, 37) with two opposed sides, each defining a flat surface;
- at least one planar sensor element (15, 22;
- 27, 29, 29';
- 37, 38, 40) supported on the carrier plate, positioned against one flat surface and having a plan outline smaller than said one surface, leaving marginal portions of said one surface of the carrier plate extending beyond the sensor element;
- and a planar heating element (19, 21;
- 32, 35, 43, 43') supported on the carrier plate;
- wherein, the heating element is positioned on at least one of the sides of the plate, placed to laterally surround at least one sensor element about a major portion thereof and located closely adjacent thereto, the heating element being positioned adjacent to and at least one sensor element, and electrically insulated from the at least one sensor element;
- and
- the sensor element occupies a portion centrally on the carrier plate with respect to the lateral dimension thereof--and the heating element is positioned at the edge side and end portions.
Dependencies are inferred from the claim text.