| 摘要 |
An elevation indicator comprising a supporting base, a reservoir for holding liquid supported on the base, an elongated staff and a flexible tube extending from the staff to the reservoir. An elongated scale is mounted on the staff for longitudinal movement relative to the staff and a transparent tube is also mounted on the staff and extends along one side of the staff adjacent the scale. A check valve is located at the top of the transparent tube and the bottom of the transparent tube is connected to the flexible tube, so that liquid can flow between the reservoir and the transparent tube.
|
