In the described device, the thermal emissivity or absorptivity of the sample is measured by substitution of the radiative heat flow between two parallel surfaces by thermal output of a heater. Fast measurements of the mutual emissivity for the range of the temperature of the radiating surface 25 K-150 K are possible. The absorbing surface has a temperature between 5 K and 10 K when LHe is used as cryoliquid. The desired measurement sensitivity is 1 mK for temperature and 0.1 {\mu}W for heat power, respectively. The diameter of the whole device is 50 mm and so it is possible to use a commercial dewar can for the cooling. The form of the sample is a round plate 40 mm in diameter and 1 mm in thickness with one tested side. The emissivity and its temperature dependency for various surface treatments can be checked immediately before application in a cryogenic system.
@article{arxiv.1610.00967,
title = {Device for measurement of thermal emissivity at cryogenic temperatures},
author = {Tomas Kralik and Pavel Hanzelka and Vera Musilova and Ales Srnka},
journal= {arXiv preprint arXiv:1610.00967},
year = {2016}
}
Comments
The eighth Cryogenics 2004 IIR international conference proceedings, Prague, Czech Republic