ASTM E408-71(2008)

1.1 These test methods cover determination of the total normal emittance (Note) of surfaces by means of portable, inspection-meter instruments. Note 1Total normal emittance ( 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 N to wavelength and spectral normal emittance [ N ()] is

Equation 1 - (See Note 1 and equation in body of E408-71(2002).)

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.

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.