Maintain the liquid nitrogen dewar

The MCT detector dewar should maintain its insulating vacuum for several years. If the vacuum is lost, the insulation will lose effectiveness and the following symptoms may occur:

• Shortened hold times and condensation (liquid nitrogen boils off much faster than usual)
• Water and atmospheric contaminants condensing on the detector window will show up in spectra as unwanted peaks
• Note that water condensation may also appear during normal detector cooling in high-humidity environments