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When to fill NOTCam with LN2

It is the task of the person on duty to check the NOTCam temperature status and possibly fill NOTCam with LN2.
  • NOTCam should be filled every morning whenever it is mounted on the telescope to make sure it stays at operating temperature. The reason for filling in the morning rather than in the afternoon is that if the temperature starts rising in the morning due to spilling at night, NOTCam will have time to come back to operating temperature before the next night starts.

  • During storage NOTCam is kept cold by the PTR and regular LN2 fillings (typically every 3-5 days). Email warnings will be sent out to staff when the detector temperature reaches above -194 degrees. Then it is time to fill it. This limit has been set very conservatively. If the PTR works well, you have plenty of time before anything becomes urgent, and you can typically wait until the next morning if the first email comes in the early evening. NB! If the PTR is not working, you should act quickly!

  • If you want to check the NOTCam temperatures more in detail, you can check the TMS monitoring on the web. You can also do ssh -l obs marissa from any terminal using the usual password. Check the temperature and pressure log file with the command tail -f /home/software/notcam/NOTCAM_temp. Each five minutes four different temperatures and the pressure is updated. The first temperature is the cold table, the next is the outer vessel (typically reflecting the dome temperature), the third is the center wheel section, and the forth is the array temperature. The last value is the pressure in mbar.

    Mon Apr  7 10:17:47 2003  1049707067  -201.60 3.80 -197.30 -196.30 4.16e-05

  • There is an automatic email sent out to all staff if the detector reaches a temperature above -194.0.

How to fill NOTCam:

How to fill NOTCam with LN2

Back to top Last modified: 21-Mar-2016