Abstract:
An improved apparatus and means for measuring temperatures inside enclosures or conduits containing hot gases laden with entrained solids using a pyrometer. The improvement involves an optical access port consisting of a high strength sight tube, a safety valve, a double sight glass, various purge connections and provisions for optical alignment. A dynamic purge system keeps the optical sight path clear during normal operation, and clears the path if it begins to become occluded during operational upsets within the enclosure or conduit. The improved optical access port is mounted on the exterior wall of the vessel or conduit.