Abstract

CARDENAS-GARCIA, D.. Design and construction of a gallium fixed-point blackbody at CENAM. Rev. mex. fis. [online]. 2015, vol.61, n.2, pp.74-76. ISSN 0035-001X.

For temperatures below silver fixed-point defined by the International Temperature Scale of 1990, a transfer radiation thermometer can be calibrated using either of two calibration schemes: a variable temperature blackbody with a standard platinum resistance thermometer as a reference, or with a set of fixed-point blackbodies. CENAM is presently working with the first scheme, and it is developing fixed-point blackbodies to have the capability to work with the second scheme too. For this purpose a gallium fixed-point blackbody to calibrate CENAM's transfer radiation thermometer was designed and constructed. The blackbody cavity has a cylindro-cone shape with effective emissivity equal to 0.9992 ± 0.0004 in the 8 μm to 14 μm wavelength range. The radiance temperature of the gallium fixed-point blackbody was estimated to have an expanded uncertainty of 54 mK, with a coverage factor k = 2.

Keywords : International temperature scale of 1990; fixed-point blackbody; radiation thermometry.

        · text in English     · English ( pdf )