Telescope Checkout

New observers should run these checks every night until they don't need to refer to the list.  In practice, telescope failures are rare and we can probably make the telescope motion checks optional.  The air quality checks should be done every night, however, and you'll still need to go to the dome to set the control switches.
Go to the dome The telescope should be at zenith and the dome should be "HOME."  If not, somebody may be working on it; check with the other observers, Telescope Engineer, and the Instrument Scientist.  If there are red hangtags on the telescope, do not attempt to move it.
Compressed air Air pressure gauges are on the wall behind the desk (photo below).  Actual pressures should match the indicated values; if not, adjust them.
Oil/water remover This is the black cylinder near eye level on the wall behind the desk. The arrow should be in the green range.
Dessicant The crystals should be blue. Notify the Telescope Engineer if they're pink or past the expiration date.
Purge air This is the vertical gauge with a little ball floating in it. Adjust to the indicated value if necessary.
Telescope sanity Verify that the telescope coordinates make sense (zenith coordinates if the telescope is at zenith, for example).
Dome sanity Verify that the dome coordinates make sense (HOME is 90 degrees aziumuth, give or take a degree or two).
Telescope on Enable all functions except the dome.  All small toggle switches on the lower left of the control panel should be "up" except the two dome switches, which should be down.  The Halt Motors button should be out, enabling telescope drives.
Telescope tracking test Verify telescope tracking by watching the HA readout. The track rate should be at or near 15.000.  It's possible to command the telescope not to track over the network (some MOP commands do this) so if the track rate shows zero but tracking is on, reset the rate to 15.000 using TCS commands and verify tracking motion.
Telescope motion test Verify telescope motion in all four directions by slewing with the handpaddle.  Check that coordinates on the screen change accordingly.  If one or more of these motions fails, the handpaddle may be faulty.  Try the other one and report the problem to the Telescope Engineer.
Dome motion test Verify dome motion, left and right, with the handpaddle. Again, try the other handpaddle if this test fails.
Check MOP/The Sky switch On the electronics rack in the corner, check that the rotary knob is pointing to "MOP" and not "The Sky."
Park telescope If you're not going to continue with flats or other telescope operations, return the telescope to zenith and push the HALT MOTORS button in. If you're going to get flats and biases, continue down the "Observing with APO20" checklist to "Point to Flat Field Screen."

 
PT Air Dryer System

Air Drying System in the 20-inch Dome

Left to right:
  1. The large black cylinder is a water & oil remover. The needle in the top gauge should be in the green area.
  2. The light blue thing with a bottle under it is filed with dessicant. The crystals should be blue. If you see any pink ones, notify the Telescope Engineer.
  3. The other light blue thing is a filter. Check the expiration date.
  4. The red plastic tube pointed up is for high pressure air to the filter box.
  5. The round dial is a regulator. Adjust it to the value indicated.
  6. The rectangular thing on the end with a black knob on the bottom is a flow regulator. Adjust the height of the little ball to the indicated value.

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minor corrections May 18, 2001
minor edits March 20, 2001
updated March 7, 2000