Raman Spectroscopy

Introduction

Raman Spectroscopy is a general-purpose experiment to create a single spectrum of a sample without any additional electrochemical measurements.

Setup Parameters

Output File: same as Optical Spectroscopy

Laser Power: Power output of laser signal in percent. See manual of Raman spectrometer for detailed information about the instrument’s power output.

Integration Time: The Integration Time is given in milliseconds (ms). This parameter defines how long the spectrometer's detector collects light.

NOTE: Longer integration times lead to a stronger signal. But if the time is too long the detector can get saturated: stronger peaks get clipped and make a measurement impractical. Check the technical specifications of the detector before using.

# to Average: Number of measured Raman spectra which are averaged to create a single spectrum.

Min Wavenumber: Minimum wavenumber (in cm–1) displayed during a measurement.

NOTE: The complete wavenumber range of the Raman spectrometer is saved in the final measurement file.

Max Wavenumber: Minimum wavenumber (in cm-1 displayed during a measurement.

NOTE: The complete wavenumber range of the Raman spectrometer is saved in the final measurement file.

Experimental Sequence

Run the Raman Spectroscopy standard technique by selecting the Named Script command under the Experiment menu in Gamry’s Framework™. Opening the RamanSpectroscopy.exp file initiates the following sequence of events:

  1. The Framework creates a runner window, and the RamanSpectroscopy.exp script is run in this window.
  2. The script creates the Setup dialog box and accepts changes in the parameters.
  3. The script obtains the use of the spectrometer, and opens the data file specified in theOutput File parameter. The runner window's title reflects the output filename. If the spectrometer is in use or the file cannot be opened, the script returns to the setup dialog box. The file header information is written to the data file. This information is written to the file prior to data acquisition. If the experiment is aborted, the output file contains only this information. This header information includes: a. Tags identifying possible analyses; b. A list of setup parameters
  4. The measurement starts if Raw Counts is selected as Spectroscopy Type (skip to number 5). The Need to acquire Dark and Blank Spectra window appears. You can decide if a dark and a blank spectrum should be recorded prior to the actual measurement:

    5. a. If you click the OK button, theAcquire Dark Spectrum window appears.

    By clicking OK again, a dark spectrum is recorded. The data of the dark spectrum are not saved. The Acquire Blank Spectrum window appears.

    By clicking OK, a blank spectrum is recorded. The data of the blank spectrum are not saved. ARuntime Warning appears.

    By clicking OK the actual measurement starts. The previously measured dark and blank spectra are automatically subtracted.

    b. If you click the Cancel button, no dark or blank spectra are recorded. For the actual measurement, Raw Counts are measured and plotted versus wavenumber.

  5. The acquired data are written to the output file and the script cleans up and halts. The script then waits for you to click the F2-Skip button. After you do so, the script closes everything that is open, including the runner window.