Taking Raman Measurements
- Load your sample vial may be loaded into the sample holder.
- Turn on the computer. Open the StellarNet software by double clicking on the desktop icon SpectraWiz to open the application.
- When you first open the software, you should see a screen that looks like:
- Click on the Setup dropdown menu and then select the Raman laser wavelength and enter the wavelength for the laser (xxx nm).
- Click on the integration time icon
and increase the exposure time to 5000 ms (5 sec). You may need to increase the integration time depending on your sample.
- Click on the Scope icon (highlighted above). This will show you the number of counts (photons) the detector receives. You should see a spectrum of counts versus Raman shifts [cm-1].
- Click on the ID icon to open the Spectral ID application. You should see a panel like:
- Turn the laser power to the lowest setting for your first trial spectrum. You should always start with the laser power as low as possible and then slowly increase it.
- Press and hold left front panel button (marked Fire Laser) to fire the laser. The LED bulb next to this button will light up red indicating that the laser is in operation. You should see a spectrum appear on the computer screen in the SpectraWiz software.
- While still holding the Fire Laser button, click on the Capture button on the Spectral ID application to collect the displayed Raman spectrum. You can then release the Fire Laser button.
- Adjust your integration time and laser power setting until you achieve the highest count spectrum in the SCOPE mode without burning the sample.
Building a Spectral Library
- After you have collected a spectrum you can save it to a spectral library. Click on Save to add a spectrum to the library. This spectrum can then be used as a reference to identify unknown compounds in other samples.
- Choose a logical name for your sample and save.
- After you have added samples to your library you can then use it to identify unknown components in a sample. Obtain a spectrum of your unknown sample (i.e. a painting) and click on the Analyze button. This will match the unknown spectrum to spectra in your library. The number next to each match indicates how closely the spectrum in the library matches the unknown spectrum (i.e. 1 indicates a perfect match).
