Skip to main content

Fourier Transform Reflectance Spectrometry between 8000 cm−1 (1.25 μm) and 800 cm−1 (12.5 μm) Using an Integrating Sphere

Buy Article:

$29.00 plus tax (Refund Policy)


Spectral measurements of the directional hemispherical reflectance of samples exhibiting variant reflection behavior were performed in the near and mid infrared spectral region using the integrating sphere method. The main components of the experimental setup were a sphere with a diffuse gold coating and a commercial Fourier transform spectrometer for the spectral analysis of the radiation incident on and reflected by the sample which is located in the center of the sphere. The capability of the device to measure absolute reflectances was tested with polished slices of high purity silicon and germanium, the reflectances of which can be calculated from the refractive indices. Agreement between the measured and calculated values was found to be within 0.01. Diffuse reflectance standards are not yet available in the infrared. The uncertainty of absolute reflectance measurements is estimated to be ±0.02. Several examples of chemical and technical applications are presented. A relatively low spectral resolution, 16 cm−1, was used to keep the measurement times short, within the range of a few minutes, thereby minimizing signal drifts. Higher resolution, sometimes necessary for special purposes in chemical analysis, can be attained by longer measurement times. No extensive sample preparation and adjustment is necessary besides the choice of the desired angle of incidence.

Keywords: Fourier transform infrared spectrometry; Integrating sphere; Reflectance (directional hemispherical); Reflectance spectrometry

Document Type: Research Article


Affiliations: Physikalisch-Technische Bundesanstalt, Braunschweig, Federal Republic of Germany

Publication date: January 1, 1983

More about this publication?

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more