Ocean Optics OOIColor - Manual (Page 10)

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If you observe that the light intensity is not very high (less than 2000 counts in scope mode), you
must either increase the integration time or move the R200 fiber optic probe closer to your
sample. If you are using an integrating sphere, using a larger diameter optical fiber will also
increase the signal intensity.
Once you find an experimental configuration that places the spectrum on scale, you are then
ready to switch back to OOIColor. Before you do, however, make a note of the integration time
that you used. Enter the integration time that you were using in OOIBase in the OOIColor
Parameters worksheet page, and make sure that the calibration coefficients of your spectrometer
are correctly entered on this page.
Go to the Acquisition worksheet page, place the white standard in the sample position, and click
on Store Reference. If you get an error box indicating that the spectrometer is not receiving the
proper amount of light, follow the instructions in the pop-up box to correct this problem. After
storing the reference, you now must store the dark spectrum. The dark spectrum is the spectrum
acquired when there is no light entering the spectrometer. If you are using an LS-1 light source,
there is a filter slot in the lamp in which you can insert a light block (a 3½” floppy disk without a
label works great). If you are using the integrating sphere, you must turn the internal light off to
take a reference. If you do, make sure that you allow the lamp to warm again up for
approximately 15 minutes before you continue acquiring data (you may even want to Store
Reference again).
After you have stored both the dark and the reference, unblock or turn on the light source and
place the substance to be analyzed in the sample location. Click on the Start Acquisition button,
and the color coordinates will be reported. To stop acquisition, simply click on the Stop
Acquisition button. To store the color space values, click on Log Values and enter a description
for the sample. They will be saved in the Stored Values worksheet page.
Field Tiles
White standards are typically expensive and easily damaged. A field tile is a rugged, inexpensive
tile which can be calibrated against the white standard. OOIColor allows you to calibrate this
field tile, and use it to reference the spectrometer. In order to calibrate the field tile, you will still
need a white standard, but you can leave this in a safe environment, and use the field tile as your
working standard.
To calibrate the field tile, go to the Acquisition page, and click on Calibrate Field Tile. This will
guide you through a series of spectral acquisitions (white tile reflection, dark spectrum and field
tile spectrum), which will compute the reflection spectrum of the field tile. This reflection data
will be stored in the Color Space and Illuminants worksheet page. After this field tile is
calibrated, you must go to the Parameters worksheet page and check the box to indicate that you
are using a Field Tile as the reference. You will then acquire data as described above, but instead
of using the white standard as the reference, you will be using the field tile that you calibrated.
This calibration only needs to be done once, as the reflection data is stored in the worksheet when
you exit and save it.