4.9 End of Night Shutdown

The end of night procedure is basically the reverse of the start-up procedure.

At the fourth floor observing area (Section 3.1):

1. Close the entrance apertures to the FTS.

2. Place the filter wheels at position 0.

3. Unlock the servo system by entering `velocity' mode.

4. Turn off power to acquisition and guide TV sets.

5. Turn off the R1/R2 oscilloscope.

6. Turn off power to main control panel.

On the fifth floor:

1. Turn off dewar preamps. BECAUSE OF THE EXTREME SENSITIVITY OF THE DETECTORS AND SINCE THEY ARE PRONE TO DAMAGE BY RADIO HANDSET TRANSMISSIONS, THIS IS A VERY IMPORTANT STEP!

2. Check the temperatures of both dewars. They normally have a holding time of approximately 24 hours. If one them indicates a value of more than 16 mV then it will be too warm by the evening and should be refilled before leaving the summit.

3. Turn off main power supply. ALL ELECTRONICS SHOULD BE TURNED OFF PRIOR TO THIS STEP.