| 摘要 |
PROBLEM TO BE SOLVED: To raise a detection precision even when a liquid level is low. SOLUTION: A water-level sensor 1 incorporates a sensor chip 5 on which a magneto-resistance element 7 is mounted. The sensor chip 5 is enclosed with a bias magnet 6, and the magneto-resistance element 7 is so arranged as to follow magnetic field from the bias magnet 6. A magnetic material 13 comprising a float 12 is housed in a space part 11 formed at the tip of the water-level sensor 1, with the magnetic material 13 moving vertically according to a water level. When the magnetic material 13 rises, the magnetic-field direction from the bias magnet 6 changes for interlinkage with magnet-resistance element 7, changing the resistance value of the magneto-resistance element 7. A detection signal is outputted according to the water level based on the resistance value, for detecting the water level. |
