|
<< Click to Display Table of Contents >> Navigation: Experiments > C - DC Corrosion > Techniques > Rp/Ec Trend > Rp/Ec Trend - Experimental Sequence |
Run the Rp/Ec Trend standard technique by selecting Experiment > DC Corrosion > Rp/Ec Trend from the Framework™ menu bar. This initiates the following sequence of events:
1.Framework™ creates a Runner window, and the RpEc Trend.exp script is run in this window.
2.The script creates the Setup dialog box. This dialog box allows you to specify parameters such as the data file name, the scan parameters for each test, and the time between tests. Clicking the OK button accepts the parameters and starts the experimental run.
3.The script now 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 information is written to the file prior to data acquisition. If the experiment is aborted, the file contains only this information. This header information includes:
•Tags identifying possible analyses.
•The current time and date.
•A list of the Setup parameters.
4.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.
5.At the start of the repetitive loop, the script checks that the total experiment time is not exceeded. If it has been exceeded, the script halts and closes the Runner window.
6.The system then runs a complete Polarization Resistance 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.
7.The actual scan occurs. The potential of the sample is swept from the Initial E to the Final E. Current readings at fixed time-intervals are taken during the sweep. At each point, the current range is automatically switched to the optimal range for the measured cell current.
8.If iR-compensation has been selected, each potential is corrected for the measured iR-drop of the preceding point.
9.When the scan is over, the cell is turned off until it is time for another test.
10.The script calculates Rp from a linear least-squares fit of the current-versus-potential data that were just recorded. The resulting data point is appended to the data file. The point is also plotted on a real-time plot of Rp and Eoc versus time.
11.The script checks the repeat cycle time and verifies if it is time to start the next curve. The script is delayed if necessary. After this delay it loops back to step 6.
12.The data are written to the output file, and the script cleans up and halts.
13.When the scan is over, the cell is turned off. The acquired data are written to the output file.
14.The script then waits for you to click the F2-Skip button. When you do, the script closes everything that is open, including the Runner window.