| 摘要 |
<p>The present invention relates to a wheel electrode (16) suitable for use with a device for making an electrical survey of a structure contained in an electrolyte. The wheel electrode includes a chamber (59) which contains electrolytic solution (56) and a porous rim (19). The rim includes a delectric rim structure having at least one recess (78) in its axial surface, a plurality of apertures (83) passing through the rim structure into the recess, and at least one porous member (50) securable in the recess and having a predetermined rate of permeation. A metal electrode (54) is positioned in the chamber in contact with the electrolytic solution. An elastic porous rim cover (51) is securable about the rim for making contact with the electrolyte. The rim cover is adapted to carry an electrically conductive solution to the electrolyte during wheel rotation. Generating mechanisms (70) are spaced about the wheel electrode at predetermined intervals for generating a series of electrical signals as the wheel electrode rotates. A count of these signals is indicative of the distance travelled by the wheel electrode.</p> |
