| 摘要 |
PURPOSE:To attain simplified construction and reduced costs, by arranging a plurality of bar-type detecting electrodes with different lengths in a concentric manner around the reference electrode placed upright along the center line of cylindrical casing and allowing the bottoms of the detecting electrodes only to be exposed from a covering insulating layer. CONSTITUTION:At the bottom of a cylindrical casing 10 is located a communicating tube fitting 11, at the upper end is a venting and overflow tube 12, and further, along the center line the bar-type standard electrode 13 is placed upright. From a insulating support piece 14 on top inside the casing 10 are suspended a plurality of bar-type detecting electrodes 15 with different lengths along a concentric periphery with the casing 10 and a level of water is measured by change of electric resistance affected significantly by the difference of that of the reference electrode 13 and bar-type detecting electrode 15. Each bar-type detecting electrode 15 is exposed from on insulating layer 15b by only an extremely short portion of metallic dielectric bar 15a for prevention of false movement caused from a leakage current. |
