13
13
TAKING TEMPERATURE MEASURE-
MENTS
To take temperature measure-
ments, connect the tempera-
ture probe, turn the instrument
on and dip the liquid/general
purpose temperature probe
HI 7662
into the sample. Al-
low the reading to stabilize.
Note
: the temperature is al-
ways displayed on the
secondary display.
AFTER USE
Turn the meter off by press-
ing the ON/OFF key again.
For a faster and accurate mea-
sure, the electrode should be
stored in a solution with a Na/
NaCl concentration similar to
the sample to be measured.
Upper the rubber sleeve after
use.
For infrequent use (once a
month or less) store the elec-
trode dry. Before using it
again, let it condition over-
night in
HI7081/HI8081
(30.0
g/L NaCl) or
HI7086/HI8086
(23 g/L Na 1M)
To avoid very long re-
sponse time, do not store
or rinse the electrode with
deionized water. Never rub
or blot the electrode.
gm
°C
NaCl
ON/OFF
ON/OFF
mannacl_r1.P65
14
14
Na CALIBRATION (HI931101)
The calibration is performed by immersing
the
FC 300B
sodium-sensitive electrode
in 2
different standard Na solutions to achieve ac-
curate 2 point calibration.
It is also possible to calibrate just the offset
(2.3 g/L Na) following the single point calibra-
tion procedure described below.
For best accuracy, a two-point calibration is
recommended (see below).
PREPARATION
• Pour small quantities of
HI7080
or
HI8080
(2.3
g/L Na) solution and
HI7087
or
HI8087
(0.23
g/L Na) or
HI7086
or
HI8086
(23 g/L Na) into
two clean beakers.
To obtain accurate readings, use HI7080/
HI8080 and HI7087/HI8087 if you are go-
ing to measure samples with low sodium
content (below 2.3 g/L) or HI7080/HI8080
and HI7086/HI8086 if you are going to
measure samples with high sodium con-
tent (over 2.3 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 minimized. Whenever
possible use plastic beakers to minimize
any EMC interferences.
• Turn the meter on by
pressing the ON/OFF key.
HI 7080
HI 7087
HI 708
0
ON/OFF
HI 7080
HI 7080
RINSE
CALIBRATION