17
17
• If the reading is not close
to the selected buffer, the
"BUF" prompt will continue
to blink.
If on the other hand, the
reading is close to the se-
lected buffer, the meter
will recognize the standard
solution. The BUF symbol
will stay still on the dis-
play, while the "
" sym-
bol will blink, indicating that
the meter is stabilizing its
reading.
• Once stabilized "CON"
symbol will appear on
the display.
Wait for a couple of min-
utes and press the CFM
key.
• The meter will return to its normal mode
and the two point calibration process is
completed.
CFM
mannacl_r1.P65
18
18
NaCl CALIBRATION (HI931100/HI931102)
The calibration is performed by immersing
the
FC 300B
sodium-sensitive electrode
in 2
different standard NaCl solutions to achieve
accurate 2 point calibration.
It is also possible to calibrate just the offset
(3.00 g/L NaCl) following the single point cali-
bration procedure described below.
For best accuracy, a two-point calibration is
recommended (see below).
PREPARATION
•
For HI931100 and HI931102:
Pour small quantities of
HI 7083
or
HI8083
(3.00 g/L
NaCl) solution and
HI7085
or
HI 8085
(0.30 g/L) or
HI 7081
or
HI 8081
(30 g/L)
into two clean beakers.
To get accurate readings use HI7083/HI8083
and HI 7085/HI8085 if you are going to mea-
sure samples with low sodium chloride con-
tent (below 3 g/L) or HI7083/HI8083 and
HI7081/HI8081 if you are going to measure
samples with high sodium chloride content
(over 3 g/L).
• For accurate calibra-
tion, use two bea-
kers for each buffer
calibration, the first
one for rinsing the electrode, the second
one for calibration. This way, contamina-
tion of the buffer is mini-
mized. Whenever possible
use plastic beakers to mini-
mize any EMC interferences.
• Turn the meter on by
pressing the ON/OFF key.
• Remove the protective cap
of the electrode and rinse
HI 7083
HI 7085
H
I
7
0
8
3
ON/OFF
ON/OFF