Sensor element used for the quantitative determination of mercury, has gold layer applied in partial surfaces in the form of bridge switch on thin carrier membrane

摘要

Sensor element (1) has a gold layer applied in partial surfaces (2) in the form of a bridge switch (37) on a thin carrier membrane (10). A separate heating layer (3) is arranged below the gold layer and can be heated to regenerate the gold layer after the quantitative determination of mercury. The gold layer, carrier membrane and heating layer are arranged on a substrate (9) which has a flat break-through (11) below the region covered by the gold layer. Preferred Features: The thin carrier membrane is made from silicon nitride. The heating layer is made from polycrystalline silicon. The gold layer is 10-100 nm thick. The bridge switch is in the form of a Wheatstone bridge. A measuring element (4) is arranged on the substrate to measure the temperature of the gold layer or to measure the temperatures of the partial surfaces of the gold layer. The active surfaces of the sensor element are connected by aluminum wires.