Water vapour sealed enclosure for optical instrument or laser - has cartridge of inert gas connected to optical enclosure through pressure reducer

摘要

The optical enclosure (1) defines a chamber (2) in which the elements (3) are located. The enclosure is closed by external optical elements such as the object lens (4) and the eyepiece (5). A cartridge (6) of an inert gas under pressure is located external to the instrument assembly and communicates permanently with the chamber through a connecting tube (7). A release valve (8) reduces the pressure from the cartridge to the chamber, and a non-return valve (9) prevents gas flow from the chamber to the cartridge. A connector assembly allows the cartridge to be replaced when insufficient gas pressure is available, as determined by a pressure sensor.