| 摘要 |
PURPOSE:To prevent the occurrence of an insulation defect of a sensor due to the diffusion of a metal, produced by reduction a metallic oxide and to the circumference of a thermistor element, by housing the metallic oxide to be sealed near the thermistor element made of the metallic oxide in air-permeable capsule-shaped covering member and arranging it. CONSTITUTION:A couple of box-shaped bodies made of stainless steel are fitted and an extremely small gap of the fitting part secures air-permeability to the outside. In addition, the gap inhibits solid particles from passing through it. In capsule- shaped covering member 6, sintered body 5 of metallic oxide (e.g., MnO2) to be reduced easier than thermistor element 2 is sealed for use. Namely, guard tube 3 containing thermistor element 2 via heat-resistant insulating powder 4 is inserted into metallic pipe 1 and at the bottom part of pipe 1, metallic oxide sintered body 5 contained in said member 6 is arranged closely to element 2, thereby forming the thermistor type temperature sensor. |
