36
For accurate calibration, use two beakers for each buffer
solution, the first one for rinsing the electrode, the second
one for calibration. By doing this, contamination between
the buffers is minimized.
To obtain accurate readings, use pH7.01 and pH4.01 if
you measure acidic samples, or pH7.01 and pH10.01 for
alkaline measurements or perform a 3-point calibration
for the entire range.
One Point Calibration (Offset)
• To perform the pH calibration enter
the calibration mode, by pressing
CAL and entering the password.
• After the correct password is en-
tered, the control actions stop and
the primary LCD will display the pH
value using the current offset and
slope, with the “CAL” and “
“
indicators lit and the probe indicator
“ “ blinking. The value displayed
on the secondary LCD is the buffer
value at the actual temperature.
Note
The actual pH value varies with temperature, thus the
calibration value displayed on the secondary LCD will vary
around pH4.01, 7.01 and 10.01 with temperature changes:
for example at 25
o
C the display shows 4.01 - 7.01 - 10.01,
at 20
o
C it shows 4.00 - 7.03 - 10.06 (see page 57 for
other values).
• pH7.01 is the default value
for the 1
st
calibration buffer.
If a different value is needed,
select it on the secondary
display by pressing
or
.
Note
If the wrong password is entered the system reverts back
and restarts displaying the pH value.
