PREPARATION OF STANDARD CALIBRATION
SOLUTIONS
Dry the potassium chloride (KCl) at 105...120°C (221...248°F) for two
hours. For a 1-mole solution, dissolve 74.555 g KCl in one litre of demine-
ralized water with conductivity less than 3 µS/cm. For a 0.1-mole solution,
dissolve 7.456 g KCl in one litre of demineralized water with conductivity
less than 1 µS/cm. For a 0.01-mole solution, add 100 millilitres of 0.1-mole
solution to 900 millilitres of demineralized water with conductivity less than
1 µS/cm.
c
0.01 M
0.1 M
1 M
T
18°C
1.225 mS/cm
11.19 mS/cm
98.24 mS/cm
19°C
1.251 mS/cm
11.43 mS/cm
100.16 mS/cm
20°C
1.278 mS/cm
11.67 mS/cm
102.09 mS/cm
21°C
1.305 mS/cm
11.91 mS/cm
104.02 mS/cm
22°C
1.332 mS/cm
12.15 mS/cm
105.94 mS/cm
23°C
1.359 mS/cm
12.39 mS/cm
107.89 mS/cm
24°C
1.386 mS/cm
12.64 mS/cm
109.84 mS/cm
25°C
1.413 mS/cm
12.88 mS/cm
111.80 mS/cm
AUTOMATIC CALIBRATION
Automatic calibration is possible with a 0.1-mole (or 0.01-mole) solution of
KCl. The temperature of the solution must be between 15°C (59°F) and
30°C (86°F), otherwise the error signal “E3” appears.
a) Switch on the instrument by pressing the ON/OFF key.
b) Immerse the conductimetry cell in the sample solution so that the elec-
trodes are covered.
c) Shake the probe gently so that any air inside it will escape.
d) Press the CAL key. The conductivity value of the solution at the probe
temperature appears on the display. For example 1278 µS at 20°C
(68°F) and the µS (or mS) symbol flashes.
e) Press the CAL key again to confirm the value displayed (or adjust this
value with the
1
and
2
keys before pressing CAL again). The µS (or
mS) symbol stops flashing.
ENGLISH
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