Galvanodynamic Experimental Sequence
Run the Galvanodynamic standard technique by selecting Experiment>DC Corrosion>Galvanodynamic from the Framework™ menu bar. This initiates the following sequence of events:
- Framework creates a Runner window, and the Galvanodynamic.exp script is run in this window.
- The script creates the Setup dialog box and accepts changes in the experimental parameters.
- The script obtains the use of the potentiostat specified during Setup, and opens the data file using the Output name. If the potentiostat is in use or the file cannot be opened, the script returns you to the Setup dialog box.
- The file header information is written to the data file. This header information includes:
This information is written to the file prior to data-acquisition. If the experiment is aborted, the output file contains only this information.
- Tags identifying possible analyses
- The current time and date
- A list of the Setup parameters
- The script conditions the electrode if Conditioning was specified in the Setup. Conditioning is done by applying a fixed potential for a defined time. It establishes a known surface state on the corrosion specimen. A plot of current versus time is displayed during the Conditioning.
- The cell is turned off, and the specimen's Eoc is measured. If an Initial Delay is turned on in the Setup, this step lasts for the time specified as the Initial Delay time, or until the potential stabilizes. If no Initial Delay is specified, this step only lasts long enough for Eoc to be measured. A plot of potential versus time is always displayed. The last measured potential is recorded as Eoc.
- The actual scan occurs. The sample is galvanostated at the Initial I, a delay of one sample period occurs, and a reading of the potential is taken. The current is then stepped, a delay of one Sample Period occurs, and the next potential reading is taken. Stepping the current, delaying and acquiring data points continues until the current equals the Final I. After each point, the potential measurement range is automatically switched to the optimal range for the measured potential. If IR-compensation has been selected, each potential is corrected for the measured IR-drop prior to displaying it or writing it to the data file. A plot of I vs. E is displayed during the scan.
- The data are written to the output file, and the script cleans up and halts.
- When the scan is over, the cell is turned off. The acquired data are written to the output file. The script waits for you to click the Skip button.
- When you do, the script closes everything that is open, including the Runner window.