Reverse Normal Pulse Voltammetry Experimental Sequence

  1. The Framework creates a runner window, and theReverse Normal Pulse Voltammetry.expscript is run in this window.

  2. The script creates the Setup dialog box, which becomes the active window and accepts changes in the experimental parameters. This Setup box remembers the experimental settings from the last time this script was run. To restore the parameters to the values defined in the script, click the Default button. If the Advanced Pstat Setup is on, a second Setup dialog box containing hardware-configuration details becomes the active window, so you can modify the hardware configuration.

  3. The script now obtains the use of the potentiostat and opens the data file using the Output File name. If the potentiostat is in use, or the file cannot be opened, the script returns you to the Setup dialog box. By default, the potentiostat’s cell switch is turned Off when the potentiostat is attached to the script.
  4. All header information is written to the data files. Header information consists of the analysis tag, the time and date the experiment was started, and a list of the setup parameters.
  5. If you selected a purge time greater than zero, the potentiostat's control bits for purge-gas flow and stirring are turned on. The effect of these bits depends on the electrode being used and the Framework™’s purge and stir settings. The script delays for the purge time, then turns Off the stirring and purge gas control bits
  6. The script delays for a time set by the Quiet Time parameter.
  7. The potentiostat is initialized. The current range is set to a range that allows the measurement of currents as big as the value of theMax I Setup parameter.
  8. The actual scan occurs.
  9. N is the number of steps that have already occurred. At the start of the scan N is zero

  10. The potential of the sample is set to the Initial E plus N times the step height If a DME, SMDE, or HDME electrode has been specified in the Electrode Settings, a New Drop pulse is issued. This potential is applied for Tstep – Tpulse. At the end of this time, a current measurement is made.

  11. The cell voltage is returned to the Initial E. This new voltage is held for Tpulse. At the end of this time, a second current measurement is made..

  12. The secoond current measurement is plotted versus the potential prior to the pulse. If Autoranging was selected in Setup and Tpulse < 20 ms, after each point the current range is automatically switched to the optimal range for the measured cell currents. Note: If Line Rejection has been checked in Setup and if the pulse time is long enough (40 ms for 50 Hz or 33.3 ms for 60 Hz), each current measurement represents the average current measured over one complete line cycle (mains cycle).

  13. Steps 10 through 12 are repeated until the potential before the pulse equals the final potential.

  14. The cell is turned off. The script pauses to allow you to view the curve you have just collected.