8
Setup can be used to view data regarding instrument status (e.g.
battery charge) or to change the meter parameters (e.g. time).
• To enter this mode press the ALT and
FNC keys when the meter is in measure-
ment mode.
• The setup code "tC" will blink on the
lower LCD and "SEt" will be displayed on
the upper one.
• Select the code of the desired
parameter using the arrow keys.
• Press the ALT and CFM keys to confirm
the code.
Note:
If the ALT and FNC keys are pressed before code confirmation,
the meter will return to measurement mode.
• If the selected parameter is password protected, the lower LCD will
display "PAS" and the password must be entered to proceed.
Otherwise, the current parameter value will be displayed.
PASSWORD PROTECTION
Setting time, date and calibration alarm time-out are password
protected and the user will be asked to enter the password to change
these parameters. After code confirmation the upper LCD will display
"0000".
• If password is set to 0000 (factory setting), just press the ALT and
CFM keys to confirm.
• If password is set to a value different from 0000, enter the
password with the up and down arrow keys and then press the
ALT and CFM keys to confirm.
• If password is incorrect the meter displays the "WRONG" indication
and asks for the password again.
• If password is correct, the meter provides access to all parameters.
SETUP MODE
FNC
ALT
ALT
GLP
FNC
CFM
RANGE
FNC
CFM
Alkaline Error
1.0 Mol L
-1
Na
+
0.1 Mol L
-1
Na
+
Sodium Ion Correction for the Glass at 20-25°C
Concentration
pH
Error
13.00
13.50
14.00
12.50
13.00
13.50
14.00
0.10
0.14
0.20
0.10
0.18
0.29
0.40
TEMPERATURE-RESISTANCE CORRELATION FOR
HANNA pH SENSITIVE GLASS
The resistance of glass electrodes partially depends on the temperature.
The lower the temperature, the higher the resistance. It takes longer time
for the reading to stabilize if the resistance is higher. In addition, the
response time will suffer to a greater degree at temperatures below 10°C.
Since the resistance of the pH electrode is in the range of 200 Mohm,
the current across the membrane is in the pico-Ampere range. Large
currents can disturb the calibration of the electrode for many hours.
For these reasons
high humidity environments, short circuits and
static discharges
are detrimental to a stable pH reading.
The pH electrode's life also depends on the temperature. If constantly
used at high temperatures, the electrode life is drastically reduced.
Typical Electrode Life
Ambient Temperature
1- 3 years
90 °C
Less than 4 months
120°C
Less than 1 month
High concentrations of sodium ions interfere with readings in alkaline
solutions; the pH at which the interference starts to be significant
depends upon the composition of the glass. This interference is the
alkaline error and causes the pH to be underestimated. Hanna's
glass formulations have the indicated characteristics.
-20 -20
-10
0
+10 +20 +30 +40 +50 +60 +70 +80 +90
° C
-10
-10
Ω
-10
-10
-10
-10
Ω
2x10
9
1x10
9
2x10
8
1x10
8
2x10
7
1x10
7
-20 -10 0
+
10
+
20
+
30
+
40
+
50
+
60
+
70
+
80
+
90
°C
25
