Measurement Of Near-Normal/Hemispherical Reflectance And Directional Emittance In The Mid-Infrared

K. Gindele; M. Kohl

doi:10.1117/12.941452

10 September 1987 Measurement Of Near-Normal/Hemispherical Reflectance And Directional Emittance In The Mid-Infrared

K. Gindele, M. Kohl

Proceedings Volume 0807, Passive Infrared Systems and Technology; (1987) https://doi.org/10.1117/12.941452
Event: Fourth International Symposium on Optical and Optoelectronic Applied Sciences and Engineering, 1987, The Hague, Netherlands

Abstract

Based on a FTIR spectrometer a measuring device for the determination of the spectral near-normal/hemispherical reflectance and the spectral directional emittance, respectively, of opaque, diffusely reflecting samples has been built up. The device is mainly used for the measuring of the spectral emittance of low-emitting selective solar absorber coatings. The measuring arrangement for hemispherical reflectance measurements with a gold coated integrating sphere is shown. The measuring geometry of the diffuse reflection attachment, the performance of the whole device as well as the calibration and evaluation of the measurements are described. Emphasis lies on the properties of the used integrating sphere and sphere design: on the angular response of the sphere and the influence of the limited reflectance and partly specularity of the sphere wall. It is shown that the integrating capacity of photometer spheres with an IR-active diffuse gold coating is partly reduced due to the relatively high deviation of the sphere wall reflectance from unity as well as due to the deterioration of the Lambertian behaviour of the wall indicated by a specular reflectance factor increasing with growing wave-lengths. Nevertheless the reflection method has some advantages over the radiometric measurement of the thermal radiation emitted by heated samples.

Citation Download Citation

K. Gindele and M. Kohl "Measurement Of Near-Normal/Hemispherical Reflectance And Directional Emittance In The Mid-Infrared", Proc. SPIE 0807, Passive Infrared Systems and Technology, (10 September 1987); https://doi.org/10.1117/12.941452

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available