Patent ID: 11906500
Assignee: GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF THE AIR FORCE
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 3:
4. The apparatus of claim 3 wherein:
a) said chamber is cylindrical or rectangular, most preferably said chamber is cylindrical;
b) said apparatus comprises three or more heat sources capable of isothermally heating three or more areas of said chamber, more preferably said apparatus comprises three or more heat sources capable of isothermally heating three or more areas of said chamber with thermal insulation between each isothermal heated zone;
c) said apparatus comprises three or more areas of optical access to said chamber for each of said at least one heat source;
d) said one or more devices for providing a pressure differential between said chamber's inlet and said chamber's outlet comprises a pump providing a pressure differential between said chamber's inlet and said chamber's outlet;
e) said one or more devices for controlling the absolute pressure in said chamber comprises a backpressure regulator located downstream of said at least one heat source;
f) each of said one or more devices for providing light to said one or more areas of optical access to said chamber is independently a laser or a light emitting diode having an emission spectrum of from about 1.99 nm to about 0.01 nm in breadth;
g) each of said one or more devices for collecting light from said one or more areas of optical access to said chamber comprises a fiber optic device having temperature tolerance above about 700° C. to about 1700° C.;
h) each of said one or more devices for measuring one or more properties of said collected light and optionally one or more properties of said provided light is independently a spectrometer or a photodiode.