1 Progress for July 17, 2011 Still plenty of snow on the Mt. It is crusty this morning.

1

Progress for July 17, 2011

Still plenty of snow on the Mt. It is crusty this morning

2

Progress for July 17, 2011

Herman and Tom continue to investigate computer communication problems. They have contacted Jim Hughes.

3

Progress for July 17, 2011

Andy attaches a connector to the RTD cables from the Dewar.

4

Progress for July 17, 2011

• Concern about Pressurized Air System Dryer – Yesterday we viewed the instrument pressurized air

system, which supplies the mirror supports, flip-ring clamps, and Mosaic filter-changer. This has an in-line Wilkerson Dryer WRD100A-2. R22 is the refrigerant.

– http://www.womackmachine.com/pdf/rb365/47th/Section5/Sec5pg246WilkersonRefrigeratedDryer.pdf is a link to a description of this model. It notes that the dryer cools the air to dewpoint 35F and can handle under normal conditions, 100 SCFM.

– The concern is that if this is the system that supplies air to the barrel, because the C5 is -5C (23F), colder than 35F, we’ll accumulate ice on its face.

Alistair assures us “This

isn’t the instrument air

that you are looking for.”

5

Next Steps & Plan

• The road is still closed. There is a lot of melting snow and it is very slippery in a few spots. We plan to stay on Tololo tonight (Sunday) through Thursday.

• Pressure test 1st thing Monday after review of JHA and other docs.

• Need to unplug/disconnect the Relay Rack before the final support post is welded under the Tank.

• Cool down still looking good for Wed. or maybe even Tues. Herman Cease is finishing off the documentation for the pressure test and cooldown.

• We plan for come down to La Serena on Thursday. Herman, Andy, and Rolando leave on Friday

6

July 17, 2011

Working on the Tank

Helium lines run down to secret staircase.