# Calculate Integrated Cottrell Equation

**Calculate Integrated Cottrell Equation** is used in charge-vs.-tau^{1/2} plots to determine the values of the parameters in the Integrated Cottrell equation for Chronocoulometry experiments. In order to use this command, you must do a linear fit on the current-vs.-tau^{1/2} plot.

## Method

- Select the
**Second Chart** tab to show the charge-vs.-tau^{1/2} plot.
- Use the
**Linear Fit** command to define a region of the plot.
- Select the
**Calculate Integrated Cottrell Equation** command from the document menu. The **Specify Linear Region to Fit** window appears.
- Click the desired line, then the
**OK** button.
- The
**Integrated Cottrell Equation** window opens. Enter three of the four parameters of the Integrated Cottrell equation. The slope of the line, with the user-entered parameters, are used to determine the value for the one unknown using the relationship that the slope = (2*nFAD*^{1/2}*C*)/π^{1/2}.