GE AKTA avant User Manual page 322

7 Maintenance
7.7 Calibration procedures
7.7.1 Calibrate the pH monitor
Step
2
3
4
5
6
7
8
9
10
322
Action
Select pH in the Monitor to calibrate list.
Click Prepare for calibration.
Result: The pH valve switches to the calibration position.
Enter the pH of the first pH standard buffer in the pH for buffer 1 box.
Fill a syringe with approximately 10 ml of the first pH standard buffer. Con-
nect the syringe to the Luer connector in pH valve port Cal, and inject the
buffer.
When the Current value is stable, click Calibrate.
Wash the pH flow cell by injecting water into pH valve port Cal using a new
syringe.
Enter the pH of the second pH standard buffer in the pH for buffer 2 box.
Repeat steps 5 to 6 using the second pH standard buffer.
Result: Calibration date and time are displayed in the dialog box, and also
values for Calibrated electrode slope and Asymmetry potential at pH 7.
Is the Calibrated electrode slope ≥ 80% and the Asymmetry potential at
pH 7 inside the interval ±60 mV?
If Yes: Click Close to switch the pH valve back to the default position,
•
and to close the Calibration dialog box.
If No: Clean the pH electrode, and repeat the calibration procedure. If
•
this does not help, replace the electrode. For information about cleaning
and replacing the pH electrode, see Section 7.5.2 Replace the pH
electrode, on page 286.
ÄKTA avant User Manual 29035184 AE