| 摘要 |
<p>The liquid level control system utilises a float (10) attached to the lower end of a hollow rod (11) of non-magnetic material, to which is attached two permanent magnets (14, 15). The upper magnet (14) is adjustable in position by means of a steel tape wound round a drum in a small casing (19). The lower magnet (15) is in a fixed posn. on the float. As the float rod moves up and down the two magnets influence a separate permanent magnet in the mechanical switch unit (22) which causes a cantilever beam to change position. The beam opens or closes the control valve to a liquid injection pump, which may be either pneumatic or hydraulic in operation.</p> |
