Table 15.

The expanded uncertainties (k = 2), in kelvin, for radiance temperature determinations of the blackbodies in the LBIR facility. As the aperture in front of the blackbody becomes smaller, the relative uncertainties become larger due to greater uncertainties in the diffraction correction and geometric alignment uncertainties

Temperature, T (K)	Aperture diameter, 2r1 (mm)
	0.204	0.284	0.405	3.214	6.407
60				0.16	0.11
70				0.16	0.12
80				0.16	0.12
100				0.17	0.13
125				0.17	0.15
145				0.18	0.16
170			1.4	0.19	0.18
195		2.11	1.38	0.21	0.2
225	2.53	2.1	1.36	0.22	0.22
250	2.56	2.1	1.35	0.24	0.25
275	2.6	2.12	1.35	0.26	0.27
315	2.69	2.16	1.36	0.29	0.3
400	2.95	2.31	1.43	0.35	0.38