title: Two-color pyrometry for low amplitude periodic heating.
abstract: Specimens subject to periodic heating must be probed for a calibrated temperature response if standard measurements of thermal diffusivity are to be extended to determine thermal conductivity. A variation on two-color pyrometry is developed to measure both the offset and harmonic amplitudes of temperature fluctuations caused by periodic heating. The requisite pyrometric formulae are derived for low amplitude heating using an expansion of the nonlinear thermal emission. Well-defined uncertainties in the temperature values are determined from experimental uncertainties in radiometric measurements. The accuracy demonstrated in this work is better than 2% for the temperature offset and 3%-8% for the fluctuating temperature amplitude.
authors.affiliation: Department of Mechanical Engineering, University of California, Santa Barbara, California 93117-5070, USA.
authors.forename: T D
authors.initials: TD
authors.lastname: Bennett
authors.affiliation: Department of Mechanical Engineering, Universidade Federal do Rio Grande do Sul Porto Alegre, Rio Grande do Sul 90050-170, Brazil.
authors.forename: V B
authors.initials: VB
authors.lastname: Silveira
authors.affiliation: Department of Mechanical Engineering, University of California, Santa Barbara, California 93117-5070, USA.
authors.forename: R
authors.identifier: 000000024012541X
authors.initials: R
authors.lastname: Valdes