| 摘要 |
The appts. comprises a tubular section of pipe (2) made from a non-magnetic material. Fluid can enter the pipe section at one end and leave at the other. The pipe section contains a mobile body (5) free to move along the length of the section but limited by end stops (6,7) which prevent it leaving the section. The mobile body (5) carries a permanent magnet (8) mounted transversely. A magnetic switch (10) mounted outside the pipe section is operated by the magnet if the mobile body moves along the pipe section under the influence of liquid flowing through the pipe section. A spring (15) may be used to return the mobile body to its rest position when the fluid flow is less than a predetermined level.
|
