Vacuum observation window, also known as vacuum viewing window, is an optical feedthrough commonly used to monitor the production situation inside vacuum containers (such as observing temperature, sample status, etc.) or transmit light sources. The glass material used to monitor the production situation inside the vacuum can be ordinary glass or transparent organic glass plate, and the glass material used to transmit light sources can be optical glass (quartz glass or sapphire glass, etc.). According to the different sealing methods of glass and flange, observation windows can be divided into detachable and non detachable types. Detachable vacuum observation windows are usually sealed with glass and flange fluororubber O-rings, which can withstand a baking temperature of 150 ° C. The flange type is usually ISO-F type, mainly used in high vacuum or rough vacuum fields. The non removable vacuum observation window adopts glass and metal sealing technology, which can withstand high temperature baking from 300 ℃ to 450 ℃. There are usually two types of flanges: CF type, mainly used in ultra-high vacuum fields, and KF type, mainly used in high vacuum or coarse vacuum fields. Vacuum Easy Buy, a global one-stop vacuum observation window shopping platform, provides thousands of different specifications of vacuum observation windows, including sapphire vacuum observation windows (27 types), quartz glass vacuum observation windows (29 types), multi-layer coating vacuum observation windows (18 types), extended optical vacuum observation windows (20 types), professional optical vacuum observation windows (20 types), non-magnetic vacuum observation windows (20 types), and positive pressure resistant vacuum observation windows (20 types)