| 摘要 |
PURPOSE:To prolong the vacuum maintaining life of a low temperature holding container by airtightly joining a metallic outer cylinder and a window to each other by a seal glass and forming the low temperature holding container. CONSTITUTION:A metallic inner cylinder 2 is provided with a package 7 comprising an infrared detecting element 6 at one end face and joined with a flange 4 made of covar at the other end. An outer cylinder 3 made of stainless steel is joined to the flange 4 which is fixed with a cylindrical window 5 made of an infrared ray transmitting material at one end face. When the window 5 is made of germanium or sapphire, the window joining portion of the outer cylinder 3 is formed by covar with a coefficient of thermal expansion close to that of germanium or sapphire. The window 5 is airtightly joined to the window joining portion of the outer cylinder 3 to form a low temperature holding container 1. Thus, by forming the container 1, a vacuum therein can be maintained for a long period. |
