A bipolar cooling plate module used in fuel cell stacks contains an anode-side terminal plate and a cathode-side terminal plate, in which at least one of the surfaces of the two terminal plates facing towards one another contains coolant channels. A search index is augmented with meta words that are traditionally not found in the documents indexed. The proximal ends of the upper and lower container bodies may be moved axially toward each other so that covering of the second opening in the lower container body is removed and then the covering of the first opening in the upper container body is removed, after which the contents of the upper and lower container bodies can be mixed with each other. The planar waveguide is attached to a side of the printed circuit board opposite to the light emitter and the light receiver. In a first period, the first capacitive sensing electrode is charged to a first voltage through the first sensing control terminal, and the second sensing control terminal supplies an electrical field pulse to the second capacitive sensing electrode such that the second capacitive sensing electrode outputs an electrical field pulse signal.