| 摘要 |
<p>A safety device for large lifting magnets uses two transducers. One transducer measures the total magnetic flux between the load and the magnet and generates a corresponding signal. The other transducer measures the load exerted on the lifting gear and also generates a corresponding signal. These two signals are compared and a signal is emitted, which indicates the margin of safety between the lifting power of the magnet and the actual load. This device is especially valuable when handling loads of apparently similar types of steel but which nevertheless may have widely different values of magnetic permeability with consequent difference in the lifting ability of the magnet.</p> |
