EFM Trend Experimental Sequence
Run the Electrochemical Frequency Modulation Trend standard technique by selecting Experiment>Electrochemical Frequency Modulation>Electrochemical Frequency Modulation Trend from the Framework™ menu bar. This initiates the following sequence of events:
- Framework creates a runner window, and the Electrochemical Frequency Modulation Trend.exp script is run in this window.
- The script creates a Runner window. In this runner window, the script displays a Setup dialog box. This dialog box allows you to specify parameters such as the data file name, the parameters for each test, and the sample parameters. Clicking the OK button accepts the parameters and starts the experimental run.
- The script now obtains the use of the potentiostat specified in the Setup dialog box. If the potentiostat is in use, or the output file cannot be opened, the script returns you to the Setup dialog box.
- The script now opens the data file specified in the setup. The file header information is written to the data file. This header information includes tags identifying possible analyses, the time and date at which the script was started, and a list of the Setup parameters. This information is written to the file before data-acquisition.
- If electrode Conditioning was specified in Setup, the script conditions the electrode by applying a known voltage for a period of time.
- The system then runs a complete EFM experiment. An optional initial delay is performed if it was requested in the setup file. In all cases, Eoc is measured at open circuit prior to the scan.
- Finally the actual measurement occurs. The composite, dual-sine-wave, waveform is applied to the cell. Current readings at fixed time-intervals are taken during the experiment. If you selected Autorange, the current scale is automatically optimized at each point in the waveform.
- At the conclusion of the EFM measurement, the data is processed based on the Corrosion Type selected in the Setup Menu. The EFM Trend data point is written to the output file and the file is closed. The data point consists of Point number, Time, Rp, Corrosion Rate, Causality Factor 2, Causality Factor 3, Icorr, BetaA, and BetaC. If Diffusion control or Passive film has been specified, the unneeded Beta is recorded as NIL.
- When the EFM experiment is over, the cell is turned off.
- If the Total Time of the trend experiment is not exceeded, the script checks the Repeat Time and delays if necessary. The sequence then repeats, beginning with step 6.
- If the Total Time of the Trend experiment has been exceeded, the script pauses to allow you to view your Trend data. Clicking F2-Skip closes the experiment. View your recently collected EFM Trend data by opening the data file with the Echem Analyst™.