1.1 These test methods cover determination of the total normal emittance (Note) of surfaces by means of portable, inspection-meter instruments.

Note 1—Total normal emittance (ε_N) is defined as the ratio of the normal radiance of a specimen to that of a blackbody radiator at the same temperature. The equation relating ε_N to wavelength and spectral normal emittance [ε_N (λ)] is

where:
L b(λ, T)	=	Planck's blackbody radiation function = c1π −1λ−5(ec2/λT − 1)−1,
c1	=	3.7415 × 10−16 W·m 2,
c2	=	1.4388 × 10−2 m·K,
T	=	absolute temperature, K,
λ	=	wavelength, m,
Lb(λ, T)dλ	=	Δπ −1T4, and
Δ	=	Stefan-Boltzmann constant = 5.66961 × 10 −8 W·m2·K−4

1.2 These test methods are intended for measurements on large surfaces when rapid measurements must be made and where a nondestructive test is desired. They are particularly useful for production control tests.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.