Multiplexed EFM Trend Experimental Setup
Run the Multiplexed EFM Trend technique by selecting Experiment>Electrochemical Frequency Modulation>Multiplexed EFM Trend from the Framework™ menu bar. This initiates the following sequence of events:
- Framework creates a runner window, and the Multiplexed EFM Trend.EXP script is run in this window.
- The script opens a Setup dialog box which becomes the active window. This dialog box allows you to specify the channels to be run, information concerning each channel, and global information about the entire experiment on all channels. Clicking the OK button accepts the parameters and starts the experimental run.
- The script opens the electrochemical parameters file (SYSTEM.SET) and recovers the electrochemical system characteristics (density, Equiv.Wt.) for each active cell from the file. If the software cannot open the file or cannot find the requested Setup Name, the script warns you and then returns you to the Setup dialog box.
- The script opens the data file associated with the each active multiplexer channel to see if there are any problems with the composite (base plus channel number) filename.
- The script now obtains the use of the potentiostat and ECM8 multiplexer specified in the script or in the Setup dialog box. It initializes the multiplexer so that all the cells are held at open circuit when they are not being measured. If the potentiostat is in use or the ECM8 cannot be opened, the script returns to the Setup dialog box.
- If the elapsed time for this experiment is greater than the total experiment time, the script complains and returns to the Setup dialog box.
- If you selected Conditioning in Setup, the local potentiostats in the ECM8 are used to condition all the ECM8 channels. This includes both channels selected for data-acquisition and cells that are not selected.
- The script switches the multiplexer to the first selected channel. A complete EFM experiment is run on this cell. An optional Init. Delay is performed prior to each scan. In all cases, Eoc is measured prior to the scan. Finally the actual EFM measurement occurs. The two-frequency composite signal is applied to the cell and the current is recorded. At the conclusion of the measurement, the potentiostat cell switch and multiplexer channel are turned off.
- The script calculates Icorr, Corrosion Rate, Tafel Constants, and Causality Factors. The resulting data point is appended to the data file for that channel and the data file is closed.
- Steps 8 though 9 are now repeated for every other active channel.
- After all the channels have been run, the script checks the repeat cycle time and delays if necessary. After this delay, it repeats the cycle though the active channels starting with step 8.