Fraunhofer Institute for Building Physics IBP
Fourier spectrometer
Energy Efficiency and Indoor Climate
To determine the radiation exchange between bodies, the emissivity of the surfaces must be known. This can be calculated by applying a specific method (e.g. DIN EN 12898), which is based on spectrophotometric measurements of the reflectance in the infrared spectrum in the wavelength range of 5 µm to 50 µm. These measurements are performed with Bruker's Vertex 70 FTIR spectrophotometer using a gold-coated integrating sphere with a diameter of 75 mm. The total emissivity is then calculated either with the aid of Planck's distribution or via the arithmetic mean of the measured values of the wavelengths specified in DIN EN 12898.
| Measurement | Emissivity (direct-hemispherical) |
| Standards | DIN EN 12898, ASTM E1980 |
| Measurement objects | Glass, sun shade, glare protection, fabric, synthetics, foil, membrane, metal, plaster, paint coating, concrete surface, coatings |
Technical data
| Measuring range | 2.5 μm to 50 μm (MIR-FIR-range) |
| Accessory | Integrating sphere (75 mm) |
| Size of test samples | Width max. 150 mm, thickness max. 9 mm other sizes on request |
Special feature
Measurement and evaluation according to international standards.