| 摘要 |
PURPOSE:To attain to simplify the constitution of the titled apparatus and to insure the reliability thereof, by constituting a bridge circuit by using a compensation element, a gas detecting element and two reference resistance elements while a temp. compensation resistance element is connected to the compensation element in parallel. CONSTITUTION:A newly used compensation element Sb has such a constitution that only a noble metal catalyst 3c is removed from a gas detecting element Sa, that is, the gas detecting element Sa is packaged without coating the noble metal catalyst 3c. Therefore, the gas detecting element Sa is thoroughly made same in a wire material 3a and a carrier 3b but, because the catalyst 3c is not equipped, is not responsive to gas. In a bridge circuit B constituted by using the gas detecting element Sa and the compensation element Sb, because the compensation element Sb itself is not responsive to the gas, a gas detecting apparatus can be stably operated even if a special gas atmosphere isolating structure as is conventional is employed. That is, because it is unnecessary to perform operation for hermetically sealing a sensor as is conventional, it is possible to attain to simplify the constitution and to reduce cost. |
