Tech Note 1082 Detail

How to measure absorbance with GLX and OO Spectrometer

Affected Products:

PS-2002 Xplorer GLX

How to measure absorbance with Xplorer GLX and Ocean Optics spectrometer

PASCO Solution:



  1. Connect the spectrometer to the GLX. (A spectrum analysis configuration window should appear.)
  2. Completely fill a clean cuvette with reference solution. (A reference is a sample of solution with none of the light-absorbing chemical of interest in it, that is otherwise identical to the solutions under test. The reference is typically pure water.)
  3. Place the reference inside the sample chamber.
  4. Press the Start button. (This should cause the Intensity versus Wavelength graph to update once per second.)
  5. Adjust the Integration Time to the largest value that keeps the top of intensity(wavelength) spectrum that still keeps the wavelength intensity from becoming flattened at the top due to over-exposure of the CCD elements.
  6. Turn the light off.
  7. Press Save Dark.
  8. Place the reference inside. (The reference is usually pure water without air bubbles. Make sure the meniscus is well above the level of the light beam.)
  9. Turn the light on.
  10. Press Save Ref.
  11. Remove the reference and place the most concentrated sample of interest in the chamber.
  12. Go to the Time Acquisition tab.
  13. Enter a wavelength value in the Wavelength box for which there is substantial absorbance, but not so much that the peak of the absorbance gets clipped off.
  14. Set the bandwidth to a value between 2-10 pixels.
  15. Change the Scan Mode to Time Acquisition.
  16. Close the Spectrum Analysis Configuration window.
  17. Press the check mark (to select the y-axis variable) and switch to Absorbance.
  18. Click Start.

Creation Date: 04/23/2010
Last Modified:
Mod Summary: