Apr-09
101
Avantes
www.avantes.com
4.8
AvaLight-DH-CAL UV/VIS calibrated light source
The AvaLight-DH-CAL is a calibrated light source for the UV/VIS/NIR spectral range (200-1099nm).
Optionally an extended calibration for the NIR spectral range (1100-2500 nm) can be ordered. This
NIST-traceable calibrated light source is developed for use with all AvaSpec spectrometers to be
used in measuring absolute spectral intensity.
The AvaLight-DH-CAL comes with a cosine corrector with SMA adapter. The software includes two
calibration files, both valid for calibration with the cosine corrector. One calibration file can be used
for irradiance calibration over the full range (200-1099nm). In that case the Deuterium and Halogen
light need to be switched on during the calibration. The other calibration file can be used for
irradiance calibration over the VIS/NIR range (350-1095nm). In that case only the Halogen light
needs to be switched on which gives a more smooth and stable output at the higher wavelengths.
Optionally an extended calibration for the NIR spectral range (1100-2500 nm) can be supplied.
The calibration files can be imported in the AvaSoft-IRRAD application software, developed to make
your spectrometer system a spectroradiometer.
Changing of the bulb
Since the light source is calibrated, the bulb exchange and recalibration can only be done in our
calibration lab.
N.B. The AvaLight-DH-CAL cannot be used as a light source for standard reflection/absorption
spectroscopy.
How to take absolute irradiance measurements with AvaSoft 7-IRRAD
1.
Start the AvaSoft 7 software, and click the Start button in the main window.
2.
Connect a fiber to the Spectrometer input port.
3.
Start the Absolute Irradiance Application software by clicking the menu option:
Application/Absolute Irradiance. Click the “Perform Intensity Calibration” button.
4.
Select the spectrometer channel that will be calibrated, the calibration lamp file and enter
the diameter of the fiber/cosine corrector or integrating sphere sample port that is used.
5.
Turn on the reference light source (e.g. AvaLight-DH-CAL or AvaLight-DH-CAL-ISP). If a cosine
corrector is used at the end of the fiber, mount it directly on the reference light source. If an
integrating sphere is used at the end of the fiber, put the integrating sphere sample port over
the light output port.
6.
Verify that the calibration lamp is ON for at least 15 minutes, and click the “Start Intensity
Calibration” button. Try to adjust the integration time while looking at the reference light,
such that the maximum count over the wavelength range is around 14000 counts. It‟s also
possible to let AvaSoft search for an optimal integration time by clicking the „ AC‟ button.
7.
Adjust the Smoothing Parameter to optimize smoothing for the Fiber/Slit diameter that is
used.
8.
If a good reference signal is displayed, click the white “Save Reference” button. A white line
will mark the reference spectrum. Then switch off the calibration lamp, wait until the
spectrum becomes flat, near the bottom of the scale, and click the black button to save a
dark spectrum. A black line will mark the dark spectrum.
9.
Click the “Save Intensity Calibration” button. A dialog shows up in which the current settings
in this intensity calibration are shown. If the calibration has been performed with diffuser,
