Spectral emissivity of surface blackbody calibrators

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    The normal spectral emissivity of commercial infrared calibrators is compared with measurements of anodized aluminum samples and grooved aluminum surfaces coated with Pyromark. Measurements performed by FTIR spectroscopy in the wavelength interval from 2 to 20 mu m and at temperatures between 5 and 550 degrees C are presented with absolute uncertainties from 0.25% to 1% in spectral regions with sufficient signal and no significant atmospheric gas absorption. A large variation in emissivity with wavelength is observed for some surfaces, i.e., from 1% to 3% to more than 10%. The variation in emissivity using similar materials can be reduced to 0.5-1% by optimizing the coating process and the surface geometry. Results are discussed and an equation for calculation of the equivalent blackbody surface temperature from FTIR spectra is presented, including reflected ambient radiation. It is in most cases necessary to correct temperature calibration results for calibrators calibrated at 8-14 mu m to obtain absolute accuracies of 0.1-1 degrees C in other spectral regions depending on the temperature. Uncertainties are discussed and equations are given for the correction of measured radiation temperatures.
    Original languageEnglish
    JournalInternational Journal of Thermophysics
    Volume28
    Issue number6
    Pages (from-to)2145-2154
    ISSN0195-928X
    DOIs
    Publication statusPublished - 2007

    Keywords

    • Blackbody
    • Calibration
    • Emissivity
    • FTIR
    • Infrared
    • Temperature

    Cite this

    @article{e7ed9874d82644198974d0938f4de7a6,
    title = "Spectral emissivity of surface blackbody calibrators",
    abstract = "The normal spectral emissivity of commercial infrared calibrators is compared with measurements of anodized aluminum samples and grooved aluminum surfaces coated with Pyromark. Measurements performed by FTIR spectroscopy in the wavelength interval from 2 to 20 mu m and at temperatures between 5 and 550 degrees C are presented with absolute uncertainties from 0.25{\%} to 1{\%} in spectral regions with sufficient signal and no significant atmospheric gas absorption. A large variation in emissivity with wavelength is observed for some surfaces, i.e., from 1{\%} to 3{\%} to more than 10{\%}. The variation in emissivity using similar materials can be reduced to 0.5-1{\%} by optimizing the coating process and the surface geometry. Results are discussed and an equation for calculation of the equivalent blackbody surface temperature from FTIR spectra is presented, including reflected ambient radiation. It is in most cases necessary to correct temperature calibration results for calibrators calibrated at 8-14 mu m to obtain absolute accuracies of 0.1-1 degrees C in other spectral regions depending on the temperature. Uncertainties are discussed and equations are given for the correction of measured radiation temperatures.",
    keywords = "Energiteknologier p{\aa} vej, Blackbody, Calibration, Emissivity, FTIR, Infrared, Temperature",
    author = "S{\o}nnik Clausen",
    year = "2007",
    doi = "10.1007/s10765-007-0287-7",
    language = "English",
    volume = "28",
    pages = "2145--2154",
    journal = "International Journal of Thermophysics",
    issn = "0195-928X",
    publisher = "Springer New York",
    number = "6",

    }

    Spectral emissivity of surface blackbody calibrators. / Clausen, Sønnik.

    In: International Journal of Thermophysics, Vol. 28, No. 6, 2007, p. 2145-2154.

    Research output: Contribution to journalJournal articleResearchpeer-review

    TY - JOUR

    T1 - Spectral emissivity of surface blackbody calibrators

    AU - Clausen, Sønnik

    PY - 2007

    Y1 - 2007

    N2 - The normal spectral emissivity of commercial infrared calibrators is compared with measurements of anodized aluminum samples and grooved aluminum surfaces coated with Pyromark. Measurements performed by FTIR spectroscopy in the wavelength interval from 2 to 20 mu m and at temperatures between 5 and 550 degrees C are presented with absolute uncertainties from 0.25% to 1% in spectral regions with sufficient signal and no significant atmospheric gas absorption. A large variation in emissivity with wavelength is observed for some surfaces, i.e., from 1% to 3% to more than 10%. The variation in emissivity using similar materials can be reduced to 0.5-1% by optimizing the coating process and the surface geometry. Results are discussed and an equation for calculation of the equivalent blackbody surface temperature from FTIR spectra is presented, including reflected ambient radiation. It is in most cases necessary to correct temperature calibration results for calibrators calibrated at 8-14 mu m to obtain absolute accuracies of 0.1-1 degrees C in other spectral regions depending on the temperature. Uncertainties are discussed and equations are given for the correction of measured radiation temperatures.

    AB - The normal spectral emissivity of commercial infrared calibrators is compared with measurements of anodized aluminum samples and grooved aluminum surfaces coated with Pyromark. Measurements performed by FTIR spectroscopy in the wavelength interval from 2 to 20 mu m and at temperatures between 5 and 550 degrees C are presented with absolute uncertainties from 0.25% to 1% in spectral regions with sufficient signal and no significant atmospheric gas absorption. A large variation in emissivity with wavelength is observed for some surfaces, i.e., from 1% to 3% to more than 10%. The variation in emissivity using similar materials can be reduced to 0.5-1% by optimizing the coating process and the surface geometry. Results are discussed and an equation for calculation of the equivalent blackbody surface temperature from FTIR spectra is presented, including reflected ambient radiation. It is in most cases necessary to correct temperature calibration results for calibrators calibrated at 8-14 mu m to obtain absolute accuracies of 0.1-1 degrees C in other spectral regions depending on the temperature. Uncertainties are discussed and equations are given for the correction of measured radiation temperatures.

    KW - Energiteknologier på vej

    KW - Blackbody

    KW - Calibration

    KW - Emissivity

    KW - FTIR

    KW - Infrared

    KW - Temperature

    U2 - 10.1007/s10765-007-0287-7

    DO - 10.1007/s10765-007-0287-7

    M3 - Journal article

    VL - 28

    SP - 2145

    EP - 2154

    JO - International Journal of Thermophysics

    JF - International Journal of Thermophysics

    SN - 0195-928X

    IS - 6

    ER -