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Aquaprobe
®
AP-7000 Instruction Manual
10401-00894 Rev M
Fluorescence measurement techniques are ideal for researchers who are interested in
detecting the presence or absence of a specific substance and measuring relative
fluorescence changes that can be used as an indication of increasing or decreasing
concentrations.
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.
If grab sample data is available, a Grab Sample Factor (GS Factor) should be calculated
and input on the calibration screen in order to improve the accuracy of future readings
15.10.3.
Special Precautions When Using the REFOIL Electrode
•
Always observe the safety advice printed above.
•
Do not deploy the REFOIL electrode in water temperatures above 30ºC.
15.10.4.
Calibrating the REFOIL Electrode
The REFOIL electrode has two calibration points. 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 REFOIL 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.
15.10.5.
Calibration Solution Preparation
In order to 'calibrate' the REFOIL electrode, a 10ppm calibration solution of 1-5,
naphthalenedisulfonic acid disodium salt should be used. This solution contains
naphthalene, an aromatic hydrocarbon, which has
similar
fluorescence characteristics to
many Refined Oils.
The 10ppm calibration solution should be freshly prepared by serial dilution from pure 1-5,
naphthalenedisulfonic acid disodium salt. The following Naphthalene salt is recommended:
Part number: 250899
Description: 1,5-Naphthalenedisulfonic acid disodium salt hydrate (95% pure)
Supplier: Sigma Aldrich
Contact:
Be sure to handle chemicals with care and to read and comply with all health and
safety advice.
15.10.6.
Serial Dilution
10ppm Napthalene salt can be prepared either as a one or two step process dependent
upon the accuracy of the scales used.
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