9
8
For accurate readings, calibration should be per-
formed (or verified) every day if measuring the same
type of samples (e.g. cheese), or every time the
sample type is changed (e.g. cheese, meat, sea
water, etc.).
The recommended working temperature is around
20-25°C (68-77°F). For greater accuracy, perform
the calibration with standard solutions at a tempera-
ture as close as possible to the temperature of the
sample.
TAKING SODIUM MEASUREMENTS
Remove the protective cap from the
FC 300B sodium electrode and, if
possible, rinse it with some of the
sample to be measured.
Shift downwards the rubber sleeve
(see picture) to have a properly work-
ing junction.
Immerse the tip of the FC300B elec-
trode (at least 2.5 cm/1") into the
sample to be tested while making
sure that the electrode junction is
completely immersed, and without
touching the bottom of the beaker.
Wait for approximately 10 to 15 minutes to allow
for the electrode to adjust and stabilize, i.e. until
no drifting is observed for at least a couple of
minutes.
During measurement, if possible,
the sample should be gently
stirred (100 rpm).
OPERATIONAL GUIDE
INITIAL PREPARATION
Each meter is supplied com-
plete with four 1.5V AA batter-
ies.
Remove the back cover, unwrap
the batteries and install them
while paying attention to their
polarity.
PROBE CONNECTION
Connect the FC 300B sodium
electrode to the BNC socket on
the top of the instrument.
Connect the HI 7662 tempera-
ture probe to the RCA socket.
The temperature probe can be
used independently to take tem-
perature measurements.
If the probe is not plugged in,
the secondary display shows
"25°C" with the "°C" indicator
blinking.
To switch the instrument on,
press and hold the ON/OFF key
for a fraction of a second.
These meters have a built-in protection against elec-
tromagnetic interferences and the holding of the
keys is to ensure that the commands are not mis-
taken for erroneous signals.
In order to take accurate measurements, make
sure the instrument is calibrated before use
(see "Calibration" sections for details).
gm
°C
NaCl
FC 300B
SODIUM
ELECTRODE
HI 7662N
TEMPERA
TURE
PROBE
MAGNETIC STIRRER
HI 190M
POWER
SPEED
ON
OFF
MAX
