| 摘要 |
1. A device for determining the active oxygen content of cast iron, iron or steel melts, having a ceramic measuring head which is secured to the end of a carrier tube and which contains an electrochemical cell consisting of a zirconium oxide material and a reference material and provided with a shield which closely adjoins the zirconium oxide material and which shields the electrochemical cell from the melt and is destroyed on immersion of the measuring head in the melt, the electrochemical cell which consists of the zirconium oxide material an the reference material being completely surrounded by a covering consisting partially of the shield closely adjoining the zirconium oxide material, characterized in that the zirconium oxide material (2) is in the form of a small tube over which the shield (8) is fitted, and in the event of the zirconium oxide tube (3) projecting with respect to the shield (8) the projecting part is provided with a preferably plastics covering which prevents the penetration of moisture during production and storage, while when the shield (8) is at least of the same length as the zirconium oxide tube (3) its bottom open end is provided with a closure (7) which prevents the penetration of moisture. |
