Thermal Qualification Facilities

The David Florida Laboratory's (DFL) Thermal Qualification Facilities (TQF) uses thermal vacuum chambers, thermal chambers, thermal conditioners, specialty chambers, and various TQF-related support facilities. Custom data processing applications are developed in-house to support these chambers and support facilities:

Thermal Qualification Facilities

Thermal vacuum chambers

This thermal vacuum chamber is used for the baking out of spacecraft subsystems and components.

  • Chamber size / working volume (horizontal cylinder): 1.0 m diameter x 1.0 m deep (3 x 3 ft)
  • High vacuum: one turbomolecular pump capable of 1,100 litres/second nitrogen
  • Pressure range (loaded): 1.3 E-3 to 1.3 E-5 Pa (1.0 E-5 to 1.0 E-7 torr)
  • Temperature:
    • heating: ambient to +150° degrees C by eight 500 W infrared lamps
    • cooling: ambient to -50° degrees C by conductive plate.

This thermal vacuum chamber is used for testing of spacecraft subsystems and components.

  • Chamber size / working volume (horizontal cylinder): 1.0 m diameter x 1.0 m deep (3 x 3 ft)
  • High vacuum: one closed loop cryogenic pump capable of 10,000 litres/second nitrogen
  • Pressure range (loaded): 1.3 E-3 to 1.3 E-5 Pa (1.0 E-5 to 1.0 E-7 torr)
  • Cooling capacity: 500 W
  • Temperature: ±140 degrees C (+284 to -220 degrees F) in gaseous nitrogen mode and -186°C (-300 degrees F) in liquid nitrogen mode.

This thermal vacuum chamber is used for testing of spacecraft subsystems and components.

  • Chamber size / working volume (horizontal cylinder): 2.5 m diameter x 2.5 m deep (8 x 8 ft)
  • Turbo pump (helium leak testing): 1,500 litres/second (3,180 CFM)
  • High vacuum: two closed loop cryogenic pumps each capable of 10,000 litres/second nitrogen
  • High vacuum (loaded): 1.3 E-3 to 1.3 E-5 Pa (1.0 E-5 to 1.0 E-7 torr)
  • Cooling capacity: 2 kW
  • Temperature: ±140 degrees C (+284 to -220 degrees F) in gaseous nitrogen mode and -186 degrees C (-300 degrees F) in liquid nitrogen mode
  • Gaseous helium shroud (horizontal cylinder):
    • for deep cryogenic (20 K nominal) applications
    • fits within liquid nitrogen shroud
    • working volume: 1.8 m diameter x 1.8 m deep (6 x 6 ft)
    • cooling capacity: 400 W
    • temperature: two controllable setpoints of 100 K (-173 degrees C / -280 degrees F) and 20 K (-253 degrees C / -424 degrees F)
    • equipped with four translational shutters to enable the unit under test to have a short term view factor of the outside environment.

This thermal vacuum chamber is used for testing of spacecraft subsystems and components.

  • Chamber size / working volume (horizontal cylinder): 1 m diameter x 2.5 m deep (3 x 8 ft)
  • High vacuum: two closed loop cryogenic pumps each capable of 10,000 litres/second nitrogen
  • Pressure range (loaded): 1.3 E-3 to 1.3 E-5 Pa (1.0 E-5 to 1.0 E-7 torr)
  • Cooling capacity: 35 kW @ -120 degrees C (-184 degrees F)
  • Temperature: +150 to -180 degrees C (+300 to -290 degrees F) using a thermal conditioning unit
  • Maximum ramp rate: 10 degrees C/ min (18 degrees F/ min).

This chamber is our largest thermal vacuum chamber and is used for testing of all-up spacecraft as well as subsystem and component level testing.

  • Chamber working size (vertical cylinder): 6.7 m diameter x 10.7 m deep (22 x 35 ft)
  • Working volume: 377 cubic m (13,300 cubic ft).

Chamber access

  • Main access for personnel is through the 2.2 m diameter (7 ft) door
  • Auxiliary access for personnel is through the 1.5 m diameter (5 ft) door
  • Access for units under test is through the removable 6.7 m diameter (22 ft) top lid
  • Internal staging is configurable to meet test requirements and is vertically adjustable.

Port sizes

  • 60 cm (24 inch) port (1)
  • 30 cm (12 inch) ports (36)
  • 20 cm (8 inch) ports (12).

Specimen supports

  • Bottom end-bell can support a maximum of 13,600 kg (30,000 lb) with a distributed load
  • Bottom end-bell hard points that are isolated from the chamber (4): 6,800 kg load (15,000 lb) each up to a maximum of 27,000 kg (60,000 lb)
  • Middle cylindrical section hard points (36): these hard points are located in six rings at different locations on the chamber wall and can support 4,500 kg load (10,000 lb) per ring up to a maximum of 13,600 kg (30,000 lb)
  • Top lid hard points (8): 275 kg load (600 lb) each up to a maximum of 2,200 kg (5,000 lb).

Thermal subsystems

  • Shroud construction: extruded aluminum
  • Shroud surface properties: CAT-A-LAC black paint; (a>0.90 (lambda = 0.4 to 20 µm) at 22 degrees C (72 degrees F)
  • Temperature: -186 degrees C (-300 degrees F) in liquid nitrogen mode
  • Cooling capacity: 1.1 solar constants / 50% shroud area, load 260 kW maximum
  • Cool down duration: from ambient to liquid nitrogen temperature in three hours (typical) after chamber is in high vacuum
  • Warmup duration: from liquid nitrogen to ambient temperature in sixteen hours (typical)
  • Liquid Nitrogen Recirculation System (LNRS) provides closed-loop liquid nitrogen cooling to client equipment through four individual zones; pressure: 690 kPa (100 psig) maximum; and heat load: 50 kW maximum.

Vacuum subsystems

  • High vacuum: Three closed loop cryogenic pumps with isolation valves that are capable of 55,000 litres/second nitrogen (117,000 CFM)
  • Pressure range in liquid nitrogen mode (loaded): 1.5 E-4 to 1.5 E-5 Pa (1.0 E-6 to 1.0 E-7 torr)
  • Turbo pump: helium leak testing, 1,500 litres/second (3,180 CFM)
  • Pump down duration: from ambient to high vacuum in eight hours (typical) including three pump / purge cycles
  • Chamber venting duration: from high vacuum to ambient in three hours (typical) including three pump / purge cycles.

Infrared lamp bank system

  • Lamps: 500 W each
  • Internal infrared structure is supplied by the client.

Thermal chambers and thermal conditioners

T1 Chamber (3.0x4.3)

This chamber is used for temperature cycling tests only. Temperatures are controlled by one of the thermal conditioners.

  • Chamber size: 3.0 x 4.3 x 2.7 m deep (10 x 14 x 8 ft)
  • Working volume: 2.8 x 4.2 x 2.4 m deep (9.2 x 13.8 x 7.9 ft)
  • Temperature range: ±100 degrees C (+212 to -148 degrees F).

This chamber is used for thermal testing as well as thermal PIM, power, and multipaction tests in association with the DFL's Radio Frequency Qualification Facilities (RFQF).

  • Chamber size: 2.7 x 3.7 x 2.7 m deep (8 x 12 x 8 ft)
  • Working volume: 1.6 x 3.4 x 1.9 m deep (5.3 x 11.2 x 6.2 ft)
  • Temperature range: +93 to -73 degrees C (+200 to -100 degrees F)
  • Temperature range in internal enclosure: +120 to -100 degrees C
    (+248 to -148 degrees F)
  • For thermal PIM testing, it is lined with RF absorber.

This chamber is our largest thermal chamber and is used for thermal testing as well as thermal PIM, power, and multipaction tests in association with the RFQF. Temperatures are controlled by one of the thermal conditioners.

  • Chamber size: 3.7 x 3.7 x 4.9 m deep (12 x 12 x 16 ft)
  • Working volume: 2.8 x 2.8 x 4.5 m deep (9.2 x 9.2 x 14.8 ft)
  • Temperature range: + 93 to -73 degrees C (+200 to -100 degrees F)
  • For thermal PIM testing, it is lined with RF absorber.
  • Cooling capacity: 23.45 kW at -140 degrees C (-220 degrees F)
  • Gaseous nitrogen flow rate: 960 litres/second (250 US gallons/second) with external static pressure of 5 cm (2 in) of water
  • Heating capacity: 18 kW
  • Working volume: 97 x 97 x 61 cm (38 x 38 x 24 in)
  • Temperature control: ±1 degrees C (±2 degrees F)
  • Temperature range: +150 to -150 degrees C (+300 to -240 degrees F)
  • Ramp rate: up to 15 degrees C /minute (27 degrees F /minute).

Specialty chambers

This chamber is used for temperature altitude testing. Temperature control is available for all virtual altitudes ranging from sea level to 12,200 m ASL (40,000 ft).

  • Working volume: 0.96 x 0.93 x 1.07 m deep (38 x 36.5 x 42 in)
  • Temperature range: +177 to -73 degrees C (+350 to -100 degrees F)
  • Temperature maximum ramp rate: 3 degrees C /minute (5.4 degrees F /minute)
  • Cooling capacity: 3 kW
  • Altitude range: sea level to 35,052 m ASL (115,000 ft)
  • Altitude maximum ramp rate: 25 m /second (5000 ft /minute).

This chamber is used for temperature humidity testing.

  • Working volume: 1.02 x 1.00 x 1.17 m deep (40 x 39 x 46 in)
  • Temperature range: +180 to -70 degrees C (+355 to -94 degrees F)
  • Maximum ramp rate (heating): 6.2 degrees C / minute (11.2 degrees F / minute)
  • Maximum ramp rate (cooling): 4.1 degrees C / minute (7.4 degrees F / minute)
  • Cooling capacity at the freezing point of water: 3 kW
  • Humidity range: 10 to 98% RH
  • Humidity control: ±2.5% RH
  • Humidity uniformity: ±1.0% RH
  • Full RH control is available from +7 to +88 degrees C (+45 to +190 degrees F).

This article is constructed of fibreglass to enable the RF testing of antennas under vacuum at ambient temperature.

  • Working volume (vertical cylinder): 1.06 m diameter x 4.00 m deep (3.5 x 13 ft)
  • High vacuum: one closed loop cryogenic pump capable of 10,000 litres/second nitrogen
  • Pressure (loaded): 1.3 E-3 Pa (1.0 E-5 torr).

Support facilities

  • Area Specifications
    • Crane: 23,000 kg (50,000 lb) gantry crane, 11 m (36 ft) hook height
    • Floor area: 325 sq m (3,500 sq ft).

  • Surface Property Measurements
    • Absorptivity / emissivity / reflectivity surface property measurements
    • Fourier transform infrared spectroscopy measurements.

  • Other Testing Capabilities
    • Outgassing studies: ASTM, NASA, ESA
    • Large Area Pulsed Solar Simulator: uses a 1.0 Solar Constant pulse to test the response of solar cells and multijunction solar cells.

  • Contamination Monitoring
    • Residual gas analysis
    • Thermal quartz crystal microbalance.

  • Testing Support Facilities
    • Potting facility for custom vacuum feedthroughs
    • Custom wiring facility
    • Helium leak detection and testing.

  • Power Supplies
    • Thermal Response And Power System (TRAPS): TRAPS supplies power (0 to 110 VDC) to infrared lamps and/or heater circuits. Voltages are manually set for every lamp or circuit
    • Automated Temperature Control System (ATCS): ATCS supplies power (0 to 110 VDC) to heater circuits (typical application). Voltages are computer-controlled; on an ATCS station, the operator enters temperature setpoints for each circuit and ATCS maintains those setpoints by controlling the associated power supplies.

Custom data processing applications

DFL-developed custom data processing applications give the technologist or computer operator access to their test or process information in a familiar visual and operational format and provide research and engineering personnel with detailed historical analysis and useful file management functions.

  • Combined Data Acquisition and Control System (CDACS)
    • CDACS is fully redundant and includes primary and redundant servers as well as primary and redundant field-control devices
    • it can read up to 11 dataloggers (1,400 thermocouples)
    • the data viewer feature allows the viewing of data in the following formats: live bar graph, live chart, live spreadsheet, historical chart, and historical spreadsheet
    • the console data server feature enables the broadcasting of logged data to client computers at regular intervals
    • the thermal equilibrium feature automatically performs a running calculation of deltaT for given thermocouples to determine when stability criteria have been met
    • the data relaying feature enables client telemetry to be sent to CDACS at regular intervals and become integrated into the CDACS database
    • the virtual channels feature enables thermocouples, data relaying, or other channels to be read into CDACS and have calculations performed on them. The results of these calculations are output as virtual channels for subsequent analysis in real-time if needed
    • the data redundancy feature copies the CDACS database to a remote computer and it does so once every every minute for the duration of the test.
  • Other Data Acquisition and Control System (ODACS)
    • the ODACS data viewer feature allows the viewing of data in the following formats: live bar graph, live chart, live spreadsheet, historical chart, and historical spreadsheet
    • on most chambers e.g., the thermal conditioners and the TH1 Chamber (1x1), etc., on-board controllers allow for the programmed operation of those chambers
    • on all chambers that do not use nitrogen e.g., the TH1 Chamber (1x1) and the TA1 Chamber (3.0x4.3), etc., can operate unattended for extended durations.