Detector Control
Defining a Waveform for an ED40, ED50, or ED50A Electrochemical Detector

You can select a preprogrammed Waveform from the Program Wizard, or define a custom waveform.

  1. In the Select Waveform Options dialog box of the Program Wizard, select Custom to create a new waveform, or select a preprogrammed waveform from the list.

     Note:

    The selected waveform must match the electrode. For guidelines, see  Selecting a Default Waveform for Integrated Amperometry.

  2. Click Next>.

    The Waveform Options dialog box appears. If you selected a preprogrammed waveform, the selected waveform’s time, potential, and integration settings are displayed in the waveform table. If necessary, the settings can be modified now (see below). The waveform can also be modified in the resulting program after completing the Program Wizard.

  3. For each step in the waveform, enter or edit the parameters listed below, and then click Enter.

    Time (Sec)

    The time at which to apply the selected potential.

     Tip:

    The maximum waveform period (the length of time from the first step in the waveform to the last) is 2 seconds. However, because only 1 data point can be collected per waveform period, the actual maximum length of a waveform period depends on the Data Collection Rate. The relationship is as follows:

    data collection rate x waveform period £ 1

    For example, if the data collection rate is 5 Hz (5 points per second), the longest waveform period allowed is 0.2 seconds. To create a longer waveform, reduce the data collection rate.

    Potential (V)

    The potential to apply between the reference and working electrode.

    Integration

    The Integration Interval option:

    No-Change keeps the setting selected in the previous step

    Begin starts integration at this point

    End stops integration

     Tip:

    Each waveform must have one integration interval. Integration cannot begin at the first step or end at the last step in the waveform.

     

  4. Select the Reference Electrode Mode.

  5. Enter the pH Lower Limit and pH Upper Limit.

    The pH is read at the start of each injection.

     Note:

    For guidelines when setting the reference electrode mode and pH limits, see  Selecting the Reference Electrode Mode with Alkaline Eluents.

 

 Tips:

To delete a step, select it in the waveform table and click Delete.

To edit an existing step, select it in the waveform table; change the time, potential, and/or integration settings; and press <Enter>.

Also, refer to:

The Control Program  The Program Wizard

How to: Creating and Modifying Programs  Manually Editing a PGM File in the Commands View