Hanna Instruments HI 4521 User Manual
Page 45
45
• When in MTC mode, if pressing
after entering
calibration and while a custom pH calibration buffer is
selected, a pop-up menu will be displayed on the LCD in
which the custom buffer and the temperature value can
be ajusted by pressing
and then
or
keys. Press
to save the modified
value and then
/
to select next /
previous value to be adjusted.
• When in ATC mode, if pressing
after enter-
ing calibration and while a standard pH buffer (with a
x.xxx resolution) or a custom pH buffer is selected, a
pop-up menu will be displayed on the LCD in which
the buffer value can be adjusted using
or
. Press
to save the new
buffer value.
• If the Automatic buffer entry type has been selected for the calibration procedure, the instrument
will automatically select the closest buffer to the measured pH value from the edit buffer group
(see
pH Setup for details).
• If the Semiautomatic buffer entry type has been selected for the calibration procedure, the instrument
will automatically select the closest buffers to the measured pH value from all the available buffers
and the used buffer value can be selected with
or
.
CALIBRATION MESSAGES
•
Wrong buffer. Please check the buffer: this message appears when the difference between the pH
reading and the value of the selected calibration buffer is significant. If this message is displayed, check
if you have selected the appropriate calibration buffer.
•
Wrong buffer temperature: this message appears if the buffer temperature is out of the defined buffer
temperature range.
•
Clean the electrode or check the buffer. Press
user that some dirt or deposits could be on the electrode. Refer to the electrode Cleaning Procedure (see page 65).
•
Slope too low. Please check the buffer / Slope too high. Please check the buffer: these messages appear
if the current slope is under 80% or over 110% of default slope. Recalibrate the instrument using fresh buffers.
•
Slope too low. Press
to clear old calibration: these messages appear as a result of an erroneous slope condition. Follow
displayed instructions.
72
Calibration Points
The user can choose between
Single Point and Multi Points calibration.
To set the calibration points:
• Use
or
to highlight the
Calibration Points
option.
• Press
to confirm your selection and then use
or
to choose the desired option
.
• Press
to confirm your selection or press
to
cancel operation.
Cell constant manual editing:
The conductivity probe can also be calibrated by entering the cell
constant value.
To edit the cell constant value:
• Use
or
to highlight the
Cell Constant option.
• Press
and then use
or
to in-
crease / decrease the value.
• Press
to preset the cell constant value to the probe
auto-recognizable default cell constant.
• Press
to confirm the new value or press
to
exit without modifying.