Gambro AK 95 S Service Manual page 140

Complete calibration:
1. Make sure there is no flow or fluid in the
AK 95 S. The inlet water must be closed.
2. Start the AK 95 S, enter the Service
menu and select Calibrations.
3. Select Transducer, External and
pH TRANSDUCER from the selection
diagram.
4. Press
5. Remove the pH sensor from the pH sensor
housing by loosening the nut holding the
pH sensor and rinse the sensor in distilled
water.
6. Check that the "REF SET" on the AK 95 S
displays pH 7.
7. Put the pH sensor in a cup with pH 7
buffer solution (ordering no. 100 810 001),
or whatever reference solution available,
which must cover the glass membrane i.e.
the level in the cup should be at least
30mm from the bottom.
8. Stir in order to achieve balance in the
buffer solution. Do not let the pH sensor
lean against the bottom of the cup.
Wait for 2 minutes.
9.* Press
the AK 95 S and wait until the calibration
display returns.
10. Rinse the pH sensor in distilled water.
11. Check that the "REF SET" on the AK 95 S
displays pH 9.
12. Put the pH sensor in a cup with pH 9
buffer solution (ordering no. 100810002)
which must cover the glass membrane i.e.
the level in the cup should be at least
30mm from the bottom.
AK 95 / AK 95 S Service Manual
HCEN 9138 Rev. 10.2005
to start calibration routine.
to set the "REF SET" value on
13. Stir in order to achieve balance in the
buffer solution. The pH sensor must not
lean against the bottom of the cup.
Wait for 2 minutes.
14.* Press and wait.
The display shows: Entering sensitivity
calibration.
15. Press to confirm that the calibration
shall continue.
16. When the calibration display returns,
START
press to load the calibration values
UF
STOP
into the EEPROM.
17. Remount the pH-sensor into the pH sensor
housing.
* If an error message is shown after this
step, check the buffer solutions, level in
the cup and repeat the procedure from
step 1. If there still is an error after 2nd
try, replace the pH-sensor.
NOTE! The pH-sensor should be changed every
eighteen month.
Calibrations
6:13