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Chapter 3
to damp heat in darkness.
The climate chamber should be able to control the temperature between -45C and
o
+180 C and relative humidity between 10% to 98% (for a temperature range of 10C
o
o
o
o
o
- 95 C). Cooling and heating rates can be up to 4.4 C/min and 4.7 C/min respectively.
However, due to introduction of an illumination source, the real cooling capacity is
lower.
For the illumination, a solar simulator of 80x80 cm was obtained from Eternal Sun
2
(Delft, The Netherlands). The solar simulator contains two types of cost-effective
lamps, which are homogenised with the help of mirrors to get a homogeneous
illumination field. Ventilators and additional cooling elements were installed chamber
to remove redundant heat produced by the solar simulator.
Since the current test samples are relatively small, only the inner 40x40 cm are used
2
and calibrated. This area was calibrated BAA according to IEC 60904-9 [2], thereby
judging spectral match, uniformity and stability. Figure 3.3 shows the solar simulator
spectrum inside the climate chamber at the sample positions. The spectrum is
measured inside the chamber to account for the filtering by the window system.
When this spectrum is compared with the AM 1.5 spectrum, most areas show a good
spectral match. However, the average intensity of the wavelengths between 900 and
1100 nm is too high, therefore the spectrum has the ‘B’ qualification. The fluctuation
Lower Left
400 Top Right
Top Left
W/cm nm) AM 1.5
2 Lower Right
Middle
Irradiance ( 200
0
400 600 800 1000
wavelength (nm)
Figure 3.3
Spectrum of the solar simulator at five positions in the climate chamber (spiked blue spectra – not all visible, since they are
very similar) compared to AM 1.5 (red spectrum).
96
to damp heat in darkness.
The climate chamber should be able to control the temperature between -45C and
o
+180 C and relative humidity between 10% to 98% (for a temperature range of 10C
o
o
o
o
o
- 95 C). Cooling and heating rates can be up to 4.4 C/min and 4.7 C/min respectively.
However, due to introduction of an illumination source, the real cooling capacity is
lower.
For the illumination, a solar simulator of 80x80 cm was obtained from Eternal Sun
2
(Delft, The Netherlands). The solar simulator contains two types of cost-effective
lamps, which are homogenised with the help of mirrors to get a homogeneous
illumination field. Ventilators and additional cooling elements were installed chamber
to remove redundant heat produced by the solar simulator.
Since the current test samples are relatively small, only the inner 40x40 cm are used
2
and calibrated. This area was calibrated BAA according to IEC 60904-9 [2], thereby
judging spectral match, uniformity and stability. Figure 3.3 shows the solar simulator
spectrum inside the climate chamber at the sample positions. The spectrum is
measured inside the chamber to account for the filtering by the window system.
When this spectrum is compared with the AM 1.5 spectrum, most areas show a good
spectral match. However, the average intensity of the wavelengths between 900 and
1100 nm is too high, therefore the spectrum has the ‘B’ qualification. The fluctuation
Lower Left
400 Top Right
Top Left
W/cm nm) AM 1.5
2 Lower Right
Middle
Irradiance ( 200
0
400 600 800 1000
wavelength (nm)
Figure 3.3
Spectrum of the solar simulator at five positions in the climate chamber (spiked blue spectra – not all visible, since they are
very similar) compared to AM 1.5 (red spectrum).
96
