1. Turn on the external lamp and wait about 30 min to stabilize it
before the measurements.
2. Turn on the CAS140B spectroradiometer.
3. Click on the IS-SPECWIN program icon to run the software.
4. Click on the Reflection icon.
5. Open the method (previously created, see Note 6).
6. Perform the measurement of the dark current:
7. The dark current can be measured manually by pressing the
corresponding button. Thus, the detector physically closes the
light beam and measures the electrical signal produced without
external stimulus. This measurement is stable and does not
have to be repeated very often. In any case, it is recommended
to repeat the black measurement every time the operating
conditions are changed (e.g., exposure time).
8. Perform the measurement of the blank (see Note 7):
For liquid samples: Place a cuvette filled with distilled water
in the cuvette holder against a reference pressed barium sulfate
plate inside the cabin.
For solid samples: Place the pressed barium sulfate plate as
white reference material inside the cabin.
9. Focus the cuvette or the plate in the “view” position of the
telescopic probe. Once focused, switch to the “measure”
position.
10. Click the R icon to perform the blank measurement.
11. Perform the measurement of the sample:
For liquid samples: Place a cuvette filled with the sample in
the cuvette holder against a reference pressed barium sulfate
plate inside the cabin.
For solid samples: Place the sample against a reference
pressed barium sulfate plate inside the cabin.
12. Click on the icon ► (or press F8) to perform the color measurement of the sample.
13. Save the measure: File/Save (Select the place to save the spectra
of the samples)/OK.
14. From the spectrum, the IS-SPECWIN program calculates the
colorimetric parameters.
15. From the carotenoid content determined by analytical techniques and the colorimetric parameters measured by spectrophotometry, look for statistical models that allow to estimate the
carotenoid concentration in other samples from the colour
measurements.
112
Paula Mapelli-Brahm et al.
before the measurements.
2. Turn on the CAS140B spectroradiometer.
3. Click on the IS-SPECWIN program icon to run the software.
4. Click on the Reflection icon.
5. Open the method (previously created, see Note 6).
6. Perform the measurement of the dark current:
7. The dark current can be measured manually by pressing the
corresponding button. Thus, the detector physically closes the
light beam and measures the electrical signal produced without
external stimulus. This measurement is stable and does not
have to be repeated very often. In any case, it is recommended
to repeat the black measurement every time the operating
conditions are changed (e.g., exposure time).
8. Perform the measurement of the blank (see Note 7):
For liquid samples: Place a cuvette filled with distilled water
in the cuvette holder against a reference pressed barium sulfate
plate inside the cabin.
For solid samples: Place the pressed barium sulfate plate as
white reference material inside the cabin.
9. Focus the cuvette or the plate in the “view” position of the
telescopic probe. Once focused, switch to the “measure”
position.
10. Click the R icon to perform the blank measurement.
11. Perform the measurement of the sample:
For liquid samples: Place a cuvette filled with the sample in
the cuvette holder against a reference pressed barium sulfate
plate inside the cabin.
For solid samples: Place the sample against a reference
pressed barium sulfate plate inside the cabin.
12. Click on the icon ► (or press F8) to perform the color measurement of the sample.
13. Save the measure: File/Save (Select the place to save the spectra
of the samples)/OK.
14. From the spectrum, the IS-SPECWIN program calculates the
colorimetric parameters.
15. From the carotenoid content determined by analytical techniques and the colorimetric parameters measured by spectrophotometry, look for statistical models that allow to estimate the
carotenoid concentration in other samples from the colour
measurements.
112
Paula Mapelli-Brahm et al.