| 摘要 |
PROBLEM TO BE SOLVED: To prevent erroneous operation and precisely detect specific gravity of an electrolyte by providing a plug body with a suspended body dipped into the electrolyte, rotatably journalling a floating body at the lower part of the trailing body, burying a magnetically sensitive switch for sensing a magnet of the floating body in the trailing body, and guiding a lead wire of the switch from the plug body to the outside. SOLUTION: A magnetically sensitive switch 11 is turned on or off by turning a floating body 7 via a shaft portion 8. The upper portion is provided with a mounting portion 2 comprising a screw portion so as to be engaged with screw to an opening in a battery jar lid for a lead-acid battery, and the lower portion is provided with a plug body 1 with a circular cross section which has a suspended body 3 and is formed from a synthetic resin. A recessed notch portion 4 is formed at the bottom part of the suspended body 3 of the plug body 1, and the floating body 7 having a semicylindrical floating body part into which a magnetic body is mixed is rotatably journalled to mounting notch parts 6 formed at both side projecting pieces 5 formed by the recessed notch. The magnetically sensitive switch 11 switched on or off by magnetism is buried over the bottom recessed notch 4 of the suspended body 3, and its lead wire 12 is guided through the plug body 1 from the upper surface to the outside. |
