Ensuring System Wellness (IC Devices)
Calibrating the Conductivity Cell (CD20/25/25A, ED40/50/50A, IC20/25/25A)

When to Calibrate:

After installing a new cell (use Method A)

Every 6 months (use Method B)

 

 

Items Needed (Method B Only):

1.0 mM KCl solution: Prepare by dissolving 0.07456 g of reagent grade KCl in one liter of 18 megohm deionized water

Backpressure tubing to provide at least 7 MPa (1000 psi). Use 0.076 mm (0.003 in) ID yellow PEEK tubing (P/N 049715)

 

Method A: For Calibrating New or Replacement Cells

  1. Open the System Wellness Control Panel for the detector (see  Opening a Wellness Control Panel).

  2. In the conductivity cell calibration entry field, type the cell calibration constant (written on a tag on the conductivity cell's cable) and press <Enter>. Chromeleon downloads the value to the detector and stores the value as the current cell calibration constant.

Method B: For Calibrating After Every 6 Months of Use

  1. Disconnect the pump output line from the injection valve.

  2. Connect the pump output line directly to the inlet of the DS3 or cell.

  3. Verify that there is a minimum of 7 MPa (1000 psi) of backpressure.

  4. Pump 1.0 mM KCl through the cell at 1.0 ml/min.

  5. If using a DS3, set the DS3 temperature to the intended operating point and allow it to reach this temperature.

  6. Allow the conductivity to stabilize for about 5 minutes.

  7. Open the System Wellness control panel for the detector (see  Opening a Wellness Control Panel).

  8. Click the calibrate script button under conductivity cell. The detector calibrates the cell and uploads a new cell calibration constant to Chromeleon. Chromeleon stores this value as the current cell calibration constant.

    After calibration, the conductivity reading should be 147.00 ± 2 mS/cm and the cell calibration constant should be between 130 and 190. If this is not the case, refer to the troubleshooting section of your detector operator's manual.

  9. Flush the KCl solution from the system by pumping deionized water through the cell. When the conductivity drops to less than 1 mS/cm, stop the pump.

  10. Reconnect the pump to the injection valve and reconnect the line from the suppressor to the cell inlet.