| 摘要 |
<p>1473715 Electro-chemical gas detector PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 17 Sept 1974 [20 Sept 1973] 40432/74 Heading G1N A cell for measuring the partial pressure of a gas (preferably of oxygen in a fluid), comprises a detection and a reference electrode immersed in an electrolyte and all separated from the fluid by an insulating membrane permeable to the gas to be measured and wherein the electrolyte is at least partially immobilized by absorption thereof in a rigid, insulating, porous material. The detection electrode at least comprises a thin coating on the rigid material and the membrane is partly provided on the electrode and partly on the rigid material, which may be sintered glass or a sintered ceramic e.g. alumina. The membrane is preferably PTFE deposited by high frequency cathode sputtering but may be polyethylene or polypropylene. It has a thickness of less than 0.5ÁM. The oxygen cell shown has a sintered glass disc 11 surrounded by a solid glass annulus 12 Gold detector electrode 16 and silver reference electrode 17 are deposited on the surface of the glass ports (which are bonded together) and the electrodes and glass surface are covered with PTFE membrane 18. KC 1 electrolyte is absorbed in the porous glass 11 and the remainder is retained by glass disc 19. Enamelled leads, 14, 15 connect with the electrodes. In an alternative embodiment a porous alumina cylinder with a central bore containing the reference electrode is used, the detecting electrode being formed on the outside with longitudinal, transverse or helical grooves.</p> |
