| 摘要 |
The vacuum meter for measuring two values of physical characteristics of a fluid comprises a box (1) housing a motor unit and amplifier movement (2). Above these is a pressure graduated dial (3) and a collar (5) fixed to the box by means of a threaded ring. This allows graduated dials to be fitted to the box as a function of the fluid being used. A plastic joint (5) and a transparent cover (8) ensure a seal for the box. In order to ensure correct positioning of the dial, a fixed pointed (7) is provided, and a scale determines where the dial should be in relation to the fixed pointer, according to a known temperature-pressure law.
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