Facility 281 is a horizontal, cylindrical, medium-sized, thermal vacuum test chamber used for thermal vacuum testing and baking out test articles. The chamber is equipped with a viewport for optical testing. The payload is mounted on a plate which is attached to rails in the chamber. |
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Mode of Operation
After the test article is instrumented with thermocouples and installed in the chamber, it is connected to the ground support equipment and data acquisition system via electrical feedthroughs. After roughing down the chamber with the mechanical pump, ultimate pressure is achieved with the cryopump. A main valve allows test set up while the pumping system is being established.
Parameters
Test Pressure: <13.3µPa (10-7 torr)
Shroud Temperature: -150°C to +150°C
Chamber Pumping Speed: 1,500 lit/sec @ 133 µPa
Evacuation Time : Atm to 13.3 Pa in 5.5 min. , 13.3 Pa to 213 µPa in 2 hrs.
Physical Characteristics
Test Volume: 3' x 4'
Payload Support: Plate on support rails
Standard Electrical Feedthroughs: 36 - 37 pin connectors
Integral Instrumentation
Pressure: T/C gauge - atm to 0.13 Pa, Capacitance manometer - Atm to 10-3 mmHg
Ion Gauge: 10-3 mmHg to ultimate
Payload Temperature: 36 thermocouple channels
Contamination Monitor: TQCM, coldfinger, cryocoil, residual gas analyzer
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