- This document is http://mol-xray.princeton.edu/xray0/CryoEvapT.html
- You can also get this in RTF format
Problems with Cryo Maintaining a Stable Temperature
Recently (8/2005) the cryo has developed a tendency to have an unstable temperature at 100K. Please check that the temperature is not fluctuating more than a few tenths of a Kelvin at running temperature (~100K) before using it. If it is varying too much, try the following fix:- Press the SCREEN button on the controller face plate to get out of PROGRAM mode
- Put the evaporator into manual mode by pressing the EVAP button.
- The red EVAP L.E.D. should light.
- Increase the EvapT temperature shown on the screen by pressing the up arrows
until it is 84 Kelvin and press ENTER. The EVAP light should flash.
Do not press the SCREEN button again or you'll take EVAP out of manual mode (the EVAL light will go out).
Running EVAP in manual mode with a slightly elevated temperature should stabilize the temperature (it will take 15-30 minutes to stabilize after you change EvapT). See page 33 of the manual (left open on the dry air compressor) for more information.