Hanna Instruments hi 98140 User Manual
14
Note: The buffer pH value, and thus the value displayed on the
lower LCD, varies with temperature. For example, at 20
o
C it
shows 4.00 -7.03 -10.06, at 25
o
C it shows 4.01-7.01-10.01.
6. Select the first buffer solution value with
and if necessary.
7. When the "CFM" symbol blinks, the read-
ing is stable and calibration can be
confirmed.
confirmed.
8. Press ALT and CFM to confirm the first buffer.
9. If everything is satisfactory the LCD will
display "Stor" and then the second buffer
value expected will be displayed (two-
point calibration). If a wrong solution or
electrode has been used or if the buffer is
polluted, "WRONG" will be displayed to
alert the user.
value expected will be displayed (two-
point calibration). If a wrong solution or
electrode has been used or if the buffer is
polluted, "WRONG" will be displayed to
alert the user.
10. If only a single point calibration is re-
quired, press CAL to exit the calibration
mode and maintain the previous slope
calibration. The instrument then checks
the electrode parameters and advises user
of abnormalities by "old probe" and "dead
probe" indications.
mode and maintain the previous slope
calibration. The instrument then checks
the electrode parameters and advises user
of abnormalities by "old probe" and "dead
probe" indications.
11. Press
or to select the second buffer value. The meter will
display the "BUF 2" indication.
12. Rinse the electrode with some of the second buffer solution or clean
water.
13. Dip the bottom 4 cm (1½") of the pH electrode in a beaker
containing the second buffer.
14. When the "CFM" symbol blinks, press ALT
and CFM to confirm the second calibra-
tion point.
tion point.