In a HPBC, the annular heat pipe along with the typical hemispherical end cap forms the isothermal blackbody cavity. The temperature uniformity is typically within 0.1°C. See the plot at bottom of page for a measured temperature profile of an Ammonia HPBC that has a temperature uniformity of within 0.05°C. Also included is the measured temperature stability of this Ammonia HPBC that is within 0.06°C over a 25 minute period.
Materials of construction are typically Aluminum, Stainless Steel, Monel, Inconel or Haynes, but other materials or coatings are possible. The heat pipe’s inner and outer surfaces are typically oxidized to provide high emissivity. The working fluid used depends on the desired operating temperature range.
Conventional choices include:
ACT is a leader in Blackbody Cavity design and manufacture.
- Ammonia: -60 – 50°C
- Methanol: -20 – 60°C
- Water: 20 – 250°C
- Cesium: 300 – 600°C
- Potassium: 400 – 1,000°C
- Sodium: 500 – 1,100°C
The HPBC is available as a custom designed device, fabricated to specific size, configuration, containment and temperature requirements. While ACT’s main focus is the HPBC, we also provide entire blackbody assemblies including heating/cooling elements and temperature controllers.