Hanna Instruments hi 98140 User Manual

16

TEMPERATURE CALIBRATION PROCEDURE

(for technical personnel only)

A two point calibration at 0.0, 50.0°C has to be performed in order
to store the new calibration data in memory.
1. Immerse the pH electrode with the built-in temperature sensor in

the 0°C temperature bath.

2. Press ALT and CALT to enter temperature calibration mode.
3. Enter the password.
4. The meter will display "0.0 °C" on the lower LCD with the "BUF 1"

and "CAL" indication.

5. When the reading is stable the "CFM" symbol starts to blink.
6. Press ALT and CFM to confirm. LCD will then display 50.0°C on

the lower LCD with the "BUF 2" indication.

7. Immerse the pH electrode with the built-in temperature sensor in

the 50°C temperature bath.

8. When the reading is stable the "CFM" symbol starts to blink.
9. Press ALT and CFM to confirm and return to normal operational

mode.

10. Set the simulator to +350 mV.
11. When the "CFM" symbol blinks, the read-

ing is stable. Press ALT and CFM to
confirm the second value.

12. The LCD will display "Stor" for a few seconds.
13. If only a two-point calibration is required, press CAL to leave the

calibration mode. Proceed with the next step for three-point
calibration.

14. The meter will display "1900 mV" on the

lower LCD with the "BUF 3" indication.

15. Set the simulator to 1900 mV.
16. When the "CFM" symbol blinks, the read-

ing is stable. Press ALT and CFM to
confirm the third value.

17. Calibration is now complete, the instrument returns to normal

operational mode.

Note: "WRONG" message notifies the user if the selected value is

wrong.