| 摘要 |
The dosing unit comprises a moving member which is pressed against a gasket mounted at the circumference of an opening in the wall of a reservoir such that a part of the surface of the moving member is in contact with a liquid inside the reservoir and a part of the surface is in contact with the medium in a compartment outside the reservoir. The gasket ensures that the liquid does not flow from the reservoir to the outside compartment and medium does not flow from the outside compartment to the reservoir except when the moving member is moved and medium adhered to its surface is dragged by the gasket. Due to the invention, an electrode is provided in the reservoir and an electric potential may thereby be established between the moving member and the liquid in the reservoir. |
