| 摘要 |
<p>A device for use in monitoring a high voltage cable, after coating with a corona retardant material in an extrusion process during curing of the coating in a contained hostile environment. It comprises a housing having a through bore with a pair of glass plates sealed in spaced relationship in the bore. The housing is adapted to be attached to the containment chamber, normally in the form of a series of tubular sections connected together in the form of a catenary, with the bore in-line with an observation aperture formed in a predetermined section of the catenary. A heater coil is arranged in the enclosure between the plates to prevent condensation build-up on the adjacent surfaces of the plates thus obscuring sight of the moving cable, and a contact heater band on the outside surface of the housing to control the temperature gradient between the catenary and the housing thereby to prevent glass breakage due to thermal stress.</p> |
