Hanna Instruments HI 9026V User Manual

Page 7

After calibrating the first point (see above), press the CAL key to end the
calibration procedure.
Note: With one-point calibration there is not “Condition” and only the frame is

shown. Calibration time-out is active.

CUSTOM BUFFER SELECTION

• For setting the custom buffer values, from pH mode press the CAL key: the

meter will start from pH 7.01 buffer.

• Press the CUSTOM BUF key and use arrows for selecting the desired value for C1.

Note: To increase the speed, keep pressed the UP or DOWN arrow key.
• Press again the CUSTOM BUF key to store the

first custom buffer and scroll to the second one.
Enter C2 with the arrow keys, then press again
CUSTOM BUF and the meter will return to the
standard buffers mode

For pH measurements of wine and must, it is recommended to set the
pH 3.00 custom buffer value.

EXPIRED CALIBRATION

The instrument is provided with a real time clock (RTC), in order to monitor the
time elapsed since the last pH calibration.
The real time clock is reset every time the meter is calibrated and the “expired
calibration” status is triggered when the meter detects a calibration time-out.
The CAL tag will start blinking to warn the user that the meter should be
recalibrated.
The calibration time-out can be set (see “Setup menu” section at page 9) from
0 (function disabled) to 14 days.
For example, if a 4 days time-out has been selected the meter would issue the
alarm exactly 4 days after the last calibration.
However, if at any moment the expiration value is changed (e.g. to 7 days),
then the alarm will be immediately recalculated and appear 7 days after the
last calibration.
Notes:
• When the meter is not calibrated or calibration is cleared (default values

loaded) there is no “expired calibration”, and the display always shows a
blinking CAL tag.

• When an abnormal condition in the RTC is detected the meter forces the

“expired calibration” status.

CONDITION

The display is provided with a 5-dot bargraph (unless the feature is disabled)
which gives indications about the electrode status after calibration as follows:

Bargraph indication

Condition value

All 5 dots steady

81 to 100% of life

4 dots steady

61 to 80%

3 dots steady

41 to 60%

2 dots steady

21 to 40%

1 dot steady

1 to 20%

1 dot blinking

Only frame is ON

No info available

The “condition” bargraph remains active for 12 hours after calibration, then
only the frame is shown.

Note: When an abnormal condition in the RTC is detected, the “condition” is

cleared and only the bargraph frame is shown on display.

CLEAN ELECTRODE

Each time the pH calibration is performed, the meter internally compares the
new calibration data with the ones previously stored.
When this comparison indicates a significant differ-
ence, the CLEAN message blinks on the LCD to
advise the user that the pH electrode may need to
be cleaned (see “Electrode Maintenance” section).
After cleaning, perform calibration.

Note: If the calibration data are cleared, the comparison is done with the

default values.