Method for measurement of emissivity and absorptivity of highly reflective surfaces from 20 K to room temperatures

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081731%3A_____%2F16%3A00464050" target="_blank" >RIV/68081731:_____/16:00464050 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1088/0026-1394/53/2/743" target="_blank" >http://dx.doi.org/10.1088/0026-1394/53/2/743</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/0026-1394/53/2/743" target="_blank" >10.1088/0026-1394/53/2/743</a>

Result language

angličtina

Original language name

Method for measurement of emissivity and absorptivity of highly reflective surfaces from 20 K to room temperatures

Original language description

We present a cryogenic method for the measurement of total hemispherical emissivity and absorptivity of various materials at temperatures from 320 K down to approximate to 20 K. In absorptivity measurement the temperature of the examined sample is kept at approximate to 5 K-35 K. Radiative heat flow between two plane parallel surfaces of 40 mm in diameter disk samples placed in a vacuum, a sample and a disk with reference surface, is absorbed by a colder sample and sinks into an LHe bath via a thermal resistor (heat flow meter). Heat flow is measured by substitution method, using thermal output of an electrical heater for heat flow meter calibration. A great deal of attention is paid to the estimation of uncertainties associated with this method. Capabilities of the instrument are demonstrated by the absorptivity and emissivity measurement of the pure aluminium sample. The expanded fractional uncertainty (k = 2) in emissivity epsilon = 0.0041 measured at approximate to 30 K for pure aluminium is less than 11% and for values of emissivity epsilon > 0.0053 measured above 60 K the uncertainties are below 7%. The method was designed primarily for the measurement of highly reflective materials like pure metals, nevertheless high emissivity of the reference sample also enables the measurement of nonmetallic materials with reasonable accuracy.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

BJ - Thermodynamics

OECD FORD branch

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Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Metrologia

ISSN

0026-1394

e-ISSN

—

Volume of the periodical

53

Issue of the periodical within the volume

2

Country of publishing house

GB - UNITED KINGDOM

Number of pages

11

Pages from-to

743-753

UT code for WoS article

000373376300005

EID of the result in the Scopus database

2-s2.0-84962454807