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Aquaprobe
®
AP-7000 Instruction Manual
10401-00894 Rev M
The Meter will wait until the readings are stable, then it will send the calibration command
to the Probe, where the calibration takes place.
During calibration, the Calibrating screen is displayed and the progress counter counts up.
If the calibration is successful, the counter will reach 100% and the following screen will be
displayed.
Output:1318mV
Calibrating
100%
Press [OK]
The Calibration Report on the top line displays the voltage output from the Turbidity
Receiver Electrode in millivolts (mV). This value is stored in the Probe's memory and can
be recalled at any time. See section
Calibration Data Storage and Retrieval.
Press OK
then ESC repeatedly to return to normal reading mode.
15.4.7.
Verifying the Zero Calibration
An accurate zero point calibration is essential to the correct operation of the turbidity
electrode. The zero point calibration can sometimes be erroneous due to small air bubbles
or microscopic suspended solids in the calibration solution. For this reason, it is important
to verify the zero point calibration before proceeding to calibrate the other points.
After calibrating the zero point, remove the Probe from the calibration bottle then reinsert,
activate the probe cleaning feature then allow the reading to settle. Check the turbidity
reading is /- 1NTU of zero. If not, re-calibrate the zero point.
15.4.8.
Calibrating the Turbidity 20 NTU & 1000 NTU Points
When calibrating the 20 NTU and 1000 NTU points,
the Zero point must be calibrated
first within the same calibration session (i.e. without turning the Aquameter
®
off)
.
Remove the Probe from the zero calibration bottle, rinse thoroughly in fresh water (if using
RapidCal solution), shake off any excess and dry the outer sleeve with a soft cloth.
Gently invert,
do not shake
,
a bottle of
20 NTU or 1000 NTU Stabilised Formazin
Turbidity Standard
solution (available from most lab supply companies) several times to
thoroughly mix.
Formazin Turbidity Standard is hazardous to your health. Be sure to handle with care
and to read and comply with all health and safety advice.
Gently pour 400mL of the solution into a clean calibration tube and drop the Probe in all the
way. Activate the probe cleaning feature in order to remove any air bubbles that may be
clinging to the electrodes.
Follow the procedure detailed above for Zero point calibration as far as step 6, then select
either 20 or 1000, dependant upon the solution the probe is in. Wait while the Meter
stabilises and calibrates.
After successful calibration, the ‘Calibrating 100%’ screen will be displayed along with the
Calibration Report, which will show the voltage output from the Turbidity Receiver Electrode
© 2017 Aquaread
®
Ltd.
www.aquaread.com
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