DoD also supported the development of the water bath blackbody and various fixed-point blackbodies
to provide source-based radiometric scales.
Max Planck recognized that blackbodies
were complex devices, as the data provided for his analysis had been obtained by some of the premier experimentalists in Germany [11-13].
The characterization of integrating spheres and blackbodies
using SI traceable standards at NIST has been the hallmark of interaction between NIST and NASA for many of the EOS instruments including the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) pre-launch sensor level calibrations.
Answers to such questions can only be found by considering the manner in which blackbodies
are constructed and utilized in the laboratory.
That is why he advocated that optically thick gases could emit as blackbodies
The Optical Technology Division (OTD) at the National Institute of Standards and Technology (NIST) has been developing techniques to calibrate heat-flux sensors using thermal radiation from high-temperature blackbodies
These materials are known to be very good physical examples of blackbodies
in the laboratory [18-21].
An exploratory study at the National Institute of Standards and Technology (NIST) with a commercial ellipsoidal radiometer showed that the responsivity could be a function of the view-angle when viewing finite aperture blackbodies
The mechanism is allowed, because laboratory blackbodies
are known to possess a small hole in their outer walls through which radiation is typically sampled.
But, laboratory blackbodies
are known to be extremely complex devices, typically involving the use of specialized nearly perfectly absorbing' materials over the frequencies of interest.
For an extensive list of references on laboratory blackbodies
and the materials used in their preparation, see .
It includes skill-building, problem-solving laboratory experiments and lectures on radiometry fundamentals, emissivity, blackbodies
, the signal measurement equation, the temperature measurement equation and NIST temperature calibration services.
Carbon-based materials, such as graphite and soot, are the closest naturally occurring examples of blackbodies
For indium, tin, aluminum, silver, gold, or copper reference blackbodies
, the cavity and the crucible are machined from high-purity, high-density graphite.
A priori, it shared nothing with the fundamental mechanism existing in graphite and soot, the two best examples of true blackbodies