Multiplexed Potentiostatic Experimental Sequence

Run the Multiplexed Potentiostatic standard technique by selecting Experiment> Multiplexed DC Corrosion> Multiplexed Potentiostatic from the Framework™ menu bar. This initiates the following sequence of events:

  1. Framework creates a Runner window, and the MUXPSTAT.EXP script is run in this window.
  2. The script outputs 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.
  3. The script opens the electrochemical parameters file (SYSTEM.SET) and recovers the electrochemical-system characteristics (βs, 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.
  4. The script opens the data file associated with the each active multiplexer channel to see if there are any problems with the composite filename. It also checks the experiment timing. Problems cause the script to return to the Setup dialog box.
  5. 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 and potentiostat. If the potentiostat is in use or the ECM8 cannot be opened, the script returns to the Setup dialog box.
  6. If you enabled Conditioning in Setup, all the channels are simultaneously conditioned. This includes both selected and non-selected channels.
  7. The open circuit is measured for all selected channels. This open-circuit potential is used to calculate initial and final potentials versus the reference electrode. The data-file header is written to the data file for all selected channels.
  8. All active channels in the ECM8 have their local potentiostats set for the initial potential. The inactive mode for all selected channels is set to Local Potentiostat mode.
  9. The data-acquisition loop begins. If the time is greater than the time at the initial potential, the final potential is applied to all active cells. If the time is greater than the total experiment time, the script goes to step 10. The system potentiostat is switched to each active cell in turn. A short current-versus-time curve at the appropriate constant potential is recorded on this cell. The average current value is recovered from the curve and written to the result curve. After the last active cell, the script waits until it is time to take the next data point. It then runs through the data-acquisition loop again.
  10. The script waits for you to click the Skip button. When you do, it closes everything that is open and terminates itself. The local potentiostats remain on at the conclusion of the experiment.