3B SCIENTIFIC PHYSICS U11337 Instrucciones De Uso página 4

4. Technical data
Measurement range:
Sensor type:
Cable:
Accuracy:
Resolution:
Reaction time:
5. Operation
•
Remove the storage flask from the electrode by
unscrewing the cap, and slide the cap off the
electrode.
•
Rinse the lower end of the electrode in the region
of the glass sphere thoroughly with distilled
water, shake off the surplus water, and dry the
electrode with filter paper.
•
Measure the temperature of the solution under
test, e.g., by using the temperature sensor Pt100
U11330.
•
Measure the pH value of the solution under test,
e.g., with the pH sensor U11350.
•
Dip the rinsed redox electrode into the solution
under test and make the measurement.
•
When the reading has remained constant for
about 1 minute, note the value.
•
In some circumstances it may take as long as 30
minutes to reach this condition.
•
Round the final reading up or down to the
nearest multiple of 5 mV, and record this value
together with the pH value and the temperature.
•
After completion of the measurement, rinse the
electrode with distilled water and give it the same
treatment as before the measurement.
•
Push the cap back onto the electrode and screw it
onto the storage flask.
6. Testing the electrode
•
Connect the electrode to the sensor box and the
sensor box to the analogue input A or B of the 3B
TM
NETlog .
•
Wait for the 3B NETlog
by showing "Probe Detect".
•
Rinse the lower end of the electrode in the region
of the glass sphere and platinum ring thoroughly
3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany •
-450 mV to +1100 mV
Combination electrode
containing Ag/AgCl gel, not
refillable
1 m coaxial cable with BNC
plug
± 4.5 mV in range from
20°C to 25°C
0.9 mV
≤ 1 s to reach 95% of final
value
TM
to recognise the sensor
Subject to technical amendments
© Copyright 2009 3B Scientific GmbH
with distilled water, shake off the surplus water,
and dry with filter paper.
•
Dip the redox electrode into the saturated
quinhydrone buffer solution with pH 7.00
(U11352) and stir the solution a few times.
•
After a few minutes the reading at 25°C should be
in the range 80 mV ± 20 mV.
•
Finally, take the redox electrode out of the buffer
solution, rinse it thoroughly again with distilled
water, and dry it with filter paper.
7. Cleaning the electrode
•
When the electrode has been in use for a long
time, clean it in dilute hydrochloric acid (HCl, 0.1
mol) for about 10 minutes, rinse it with distilled
water, and regenerate it by dipping it into the
saturated quinhydrone buffer solution with pH
7.00 (U11352).
•
After completing the cleaning of the electrode,
rinse it with distilled water and give it the same
treatment as before the cleaning operation.
•
Push the cap onto the electrode and screw it onto
the storage flask.
•
Keep the redox electrode in the storage solution
for 8 hours and then use it again.
8. Examples of use
Monitoring chemical reactions.
Monitoring the decontamination of water by
electrochemical reduction of chromate or oxidation of
cyanide.
Checking swimming-bath water that has been
sterilised by the addition of free chlorine; typical
redox values found in such measurements are in the
region of 700 mV.
www.3bscientific.com