Aquaprobe
®
Lite Instruction Manual
10401-00976 Rev F
Fluorescence measurement techniques are not ideal for quantitative measurement.
In
order to obtain more accurate results, data obtained with the fluorometer in the field
should be post-calibrated with data from standard laboratory analysis of grab
samples acquired during the study.
11.10.3.
Calibrating the CDOM Electrode
The CDOM electrode has two calibration points, zero and 100ppb (100µg/L). Careful
calibration is essential in order to ensure consistent and reliable results.
It is important to
calibrate this electrode as close to operational temperature as possible.
When a CDOM electrode is first installed,
it MUST be calibrated at both points
in order to
set the electrode's relative sensitivity and establish its slope.
Subsequently, zero point calibration should be carried out before each use and full two-
point calibration should be carried out every few months.
11.10.4.
Calibration Solutions
Scientists have not developed a standard way to report CDOM values. Results are
therefore expressed in relative units based on calibration to a standard fluorescing
compound, usually quinine.
In order to 'calibrate' the CDOM electrode, a 100ppb solution of Quinine Sulphate in
sulphuric acid can be used. However, since Quinine Sulphate is extremely expensive and
sulphuric acid is dangerous to handle, Aquaread Ltd has formulated an equivalent, non
toxic standard for use during CDOM electrode calibration. This is available in 600mL
bottles.
Part number: CDOM-CAL-600
Supplier: Aquaread Ltd
Contact:
11.10.5.
Zero Point Calibration
To calibrate the zero point, follow these steps:
1. Pour 300mL of de-ionised water into a clean calibration cup, remove the storage cap
from the pH electrode if fitted, wash the Probe in mineral water, then gently lower the
Probe in all the way.
The Sleeve End Cap must be fitted
. Activate the probe
cleaning feature in order to remove any air bubbles that may be clinging to the
electrode.
2. Switch the Aquameter
®
on and wait until the temperature and CDOM readings are
stable. If the CDOM reading is very high, there are probably air bubbles adhering to
the lenses.
3. Ensure the temperature of the solution is between 5ºC and 40ºC (41ºF - 104ºF).
4. Press the
MENU
key then select
Calibration.
The following screen will be displayed.
Calibration
RapidCal
DO 100%
Full Cal
© 2015 Aquaread
®
Ltd.
www.aquaread.com
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