Elimination of reflection errors in emissometers by using alternate apertures.
Rev Sci Instrum 1976 Oct; 47(10):1279-1282
Modifications to an existing vacuum emissometer are described that allow mathematical elimination of reflecting errors of the specimen- window-specimen-detector type. Normal total emittance in the range 20 deg to 600 deg c can be determined. Successive radiance readings ls and ls' are obtained using alternate full- and reduced-size apertures. A separate run on a blackbody crucible allows determination of the corresponding lbb and lbb' values at the same temperature. The equation for true emittance is shown to be e = ls - ls' / lbb - lbb'.
OP; Journal Article
Review of Scientific Instruments