| 摘要 |
Two mechanically-connected, vertical manometer tubes forming sight glasses (1, 2) share a common headspace containing air. The manometer tubes are connected by flexible tubing (7, 8) to initial and target locations. The common headspace is connected to a source of reduced pressure, and the tubes are filled with liquid (12). Remote ends of the tubing are arched (9, 10) in a vertical plane. Near the instrument, there is a shut-off valve (11) on at least the tubing (8) associated with the target. Liquid is supplied drop-by-drop through connections (5, 6) into the headspace. |
