| 摘要 |
PURPOSE:To make a gas detecting element endurable without deterioration due to reaction with heater or gas by using crystallized glass that has a specified composition as a protective film for a heater that is provided in a gas sensitive body. CONSTITUTION:A heater provided in a gas sensitive body is covered by crystallized glass that contains 2.5-48% of SiO2 and 8-24% of Al2O3 for forming vitrified body and 5-40% of PbO as a flux and 5-25% of TiO2, 4-20% of CaO, below 5% of ZrO2 and below 20% of Zn as nucleating agent at crystallizing and below 3% of Sb2O3 as a clarifier. With such protective covering, change with time in the heater becomes little. |
