| 摘要 |
PURPOSE:To prevent the adhesion of impurities in an exhaust gas to the outside peripheral face side of a detecting element by filling the space between a protector and the detecting element with adsorbent balls. CONSTITUTION:A zirconia tube 5 is formed to a U-shaped section and generates electromotive force between an outside electrode 7 and an inside electrode 8 when a difference in concn. arises in the oxygen between the inside and outside. The protector 9 formed to a capped cylindrical shape in order to protect the projecting part of the tube 5 is formed with plural long holes 9A, 9A... on the peripheral face thereof. The small-diameter adsorbent balls 21 are packed into the space A between the protector 9 and the projecting part of the tube 5. The respective balls 21 are formed to a spherical shape by calcining, for example, porous ceramics materials such as alumina added with <=0.3wt.% platinum and are formed to about 2-6mm diameter. Many pieces of the balls 21 are disposed so as to fill the space A at a prescribed volume ratio of the space A, for example, about 80-95%. |
