Image Details
Caption: Figure 22.
Focal plane environmental measurements over the initial 22 months of operations, including both commissioning and regular survey ops, which started in 2021 May. Grayed zones are seasonal, maintenance, and Covid-19 shutdown times, during which temperature and humidity are allowed to track exterior ambient conditions. Left: while exterior air temperature varies from −7° to +30°C, the air inside the enclosure stays within ∼+10° to +15°C. Middle: while ambient dew point may drift as high as +17°C (much higher than the hardware), the dew point inside is suppressed to ∼−50° to −20°C, preventing condensation. Right: the system controls the temperature of the FPR (the large aluminum ring to which petals are mounted) to a set point of 11°C. Coolant is typically about 5° to 8° lower, removing the heat load of both the focal plane equipment itself, as well as parasitic heat absorbed along the 50 m hose run from the chiller to the enclosure.
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© 2022. The Author(s). Published by the American Astronomical Society.
