LIQUID NITROGEN DEWARS

SBF's Pour-Fill dewars are integral camera heads that combine a lens mount, FPA cooling system, and electronics housing. Pour-Fill dewars provide cooling by directly filling a reservoir with Liquid Nitrogen as opposed to Integrated Detector Dewar/Cooler Assemblies that utilized cryocooler technology. Pour-Fill dewars have the advantages of lower cost, ability to readily trade-out items such as cold filters, lower power consumption, and no vibrations due to cryocoolers. SBF's Pour-Fill dewars are designed and fabricated to enable you to run your infrared system all day on a single fill.

This dewar holds 1/3 liter of liquid nitrogen and weighs about nine pounds when full. The dewar is 206 mm high, 318 mm long, and 102 mm wide. Once cold (refill nitrogen after initial boil-off) the dewar will hold at operating temperature for 20 hours if the FPA is not powered on, and for more than 9 hours if the FPA is powered on. The dewar is available in forward looking and down looking versions to better suit different applications. A popular option for systems with pour-fill dewars is the cold filter wheel assembly which enables a number of cold filters to be installed at one time and switched externally by the user.

Front view showing lens mount.

Down-looking dewar for applications with scenes located below the camera head.