It remains true that blackbodies
are specialized cavities which depend entirely on the nature of their walls [7,9-12, 26,27].
DoD also supported the development of the water bath blackbody and various fixed-point blackbodies
to provide source-based radiometric scales.
Robitaille and Crothers also argue that Planck incorrectly includes transmission within the material of the black body when in fact, Robitaille and Crothers claim, absorption must all occur at the surface: "Blackbodies
are opaque objects without transmission, by definition" [10, p.
Step 3: To compare model predictions and validate system level calibration measurements, m is determined pre-launch for an end-to-end remote sensing instrument by viewing uniform sources of known radiance, such as well-characterized and calibrated integrating sphere sources and blackbodies
. 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.
are usually brought to temperature using conduction.
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
. Past calibrations at other laboratories and round-robin experiments demonstrated large differences in the measured responsivity of these sensors.
This remains a significant departure from the other laws of thermal emission [3-6] which have been confirmed through the construction of laboratory blackbodies
. In addition, The Law of Equivalence, first formulated by Balfour Stewart , has also been confirmed experimentally.
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
In truth, Planck's equation was only valid for laboratory blackbodies
constructed from highly absorbing materials.
The Low-Background Infrared (LBIR) facility provides means to calibrate low power thermal-infrared sources (blackbodies
At the same time, it implies that all materials used to assemble blackbodies
will act as Lambertian emitters/reflectors.
Key words: blackbodies
; heat flux; sensors; thermal radiation; transfer calibration.
In the laboratory, blackbodies
are specialized, heated, and opaque enclosures, whose internal radiation is determined by the Planckian function [2, 3].
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.
These materials are known to be very good physical examples of blackbodies
in the laboratory [18-21].