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Aquameter
™
Series Instruction Manual
10401-00188 Rev M
Never place the entire Aquaprobe in methyl alcohol, as this will cause irreparable
damage to the DO/EC electrode. Damaged caused in this way is not covered by the
warranty.
If the methyl alcohol rinse does not restore the electrode, perform the following actions:
1.
Remove the electrode from the body again.
2.
Soak in 0.1M HCl for 5 minutes.
3.
Rinse in de-ionised water.
4.
Soak in 0.1M NaOH for 5 minutes.
5.
Rinse in de-ionised water.
6.
Soak in pH4.01 buffer for 10 minutes.
If the above procedure still does not restore performance, replace the electrode.
13.7. Calibrating ORP
ORP electrodes should be calibrated at least once a month to ensure optimum accuracy.
Full calibration involves calibrating at a single point, either 231mV (at 25
°
C) for Aquaprobes
running software versions 2.00, 2.01, 2.02, 2.03, 3.00 and 3.01, or 250mV (at 25
°
C) for
Aquaprobes running software version 2.04 or 3.02 and above.
To calibrate at 231mV, use Zobell ORP calibration solution. To calibrate at 250mV, use a
250mV ORP calibration standard such as
Reagecon RS250 Redox Standard,
or similar.
Zobell OPR Calibration solution is hazardous to your health. Be sure to handle with
care and to read and comply with all health and safety advice.
On Aquaprobe Models AP-100, AP-400, AP-500 or AP-600 you must have an ORP
electrode fitted and the Aquameter must be set to read ORP. If your Aquameter is set to
read pH or pHmV, access to ORP calibration will be barred.
On Aquaprobe Models AP-700, AP-800, AP-900 and AP-1000, a dual pH/ORP electrode is
always fitted and this setting is automatic.
For best results, calibrate as close to 25
°
C as possible. The probe will automatically
compensate for temperature variation in the calibration solution during calibration.
To calibrate the ORP electrode follow these steps:
1.
Make a note of your Aquaprobe's software version (displayed on the
Aquameter screen shortly after switch on) and obtain the appropriate
calibration solution (either 231mV or 250mV standard).
You must use
the appropriate calibration solution for your software version or a
19mV offset will be introduced to all your ORP readings.
2.
Fill a 300mL calibration bottle with fresh calibration solution, remove
the storage cap from the pH/ORP electrode, wash the Probe in distilled
water, then drop the Probe in all the way.
3.
Switch the Aquameter on and wait until the temperature and ORP
measurements are completely stable.
© 2011 Aquaread Ltd.
www.aquaread.co.uk
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