| 摘要 |
A support box (1) is provided comprising a base (2) inside which a cover is screwed and glued. The inside of the structure communicates with the outside via a pipe (5). Inside the device is a circular substrate made of ceramic material with thin film resistance elements deposited on the substrate. The elements are connected in a bridge circuit by conductive tracks, and are connected to a differential amplifier on a printed circuit board beneath the substrate. - A potentiometer is mounted in an adjoining space, in order to adjust the balance point of the bridge. The diagonal points of the bridge provide a voltage applied to the amplifier, which has a feedback resistor, producing an output signal.
|
