| 摘要 |
PURPOSE:To obtain the same characteristic in an optional ultralow temperature as that at room temperature by providing a moving quantity regulating means regulating moving quantity of a gap between magnetic poles in response to the temperature change and a moving means moving one magnet according to the regulated value. CONSTITUTION:At least one magnet 6 in magnets 5, 6 is made movable, different magnetic poles are opposed to each other and a ferrite member 3 is arranged between both the magnetic poles, and the moving quantity regulating means 8 regulating the moving quantity of the magnet 8 in response to the low temperature as the operating environment and the moving means 7 moving the magnet 6 by a specified value depending on the output signal are provided. The means 8 measures in advance the change in the magnetic field applied to the magnetic path comprising the magnets 5, 6 and the ferrite 3 against the temperature change from room temperature to an ultralow temperature, stores the gap between the magnetic poles to correct the change and reads the gap between the magnetic poles corresponding to the low temperature in use and gives the result to the means 7 as an output. The moving means 7 moves the magnet 6 by the said correcting gap to make the magnetic field the same as that at room temperature.
|
