| 摘要 |
PURPOSE:To detect reliably a water level for a long term even under the condition of high temp. and pressure by composing an insulator from an electrical insulating ceramic body, and providing a film-shaped electrode formed on said ceramic body. CONSTITUTION:On an alumina porcelain green sheet as the electrical insulating ceramic body 1, the electrode 2, a conductor passage 3, and a signal terminal 4 are printed by screen printing method using platinum and alumina paste in which volume ratio of platinum to alumina is 50:50. Said body is dried, then said green sheet as an electrical insulating ceramic cover layer 5 is attached thereon under heating and pressing. This is calcined in one body at 1,500 deg.C in air, and an aimed water level detecting element is obtained. By such a water level detecting element, the water level can be detected reliably for a long term even under the condition of high temp. and pressure. |
