Ref. No. [UMCES] CBL 2013-020
ACT VS12-03
(excitation/emission) for detecting fluorophores of interest. The excitation and emission filters
are oriented at 45 degree angles to one another to allow fluorescence detection at a 90 degree
angle. The Refined Fuels sensor uses a deep UV LED (260 nm) for excitation and detects
compounds that fluoresce between 300-400 nm. Both the Crude Oil and CDOM sensors use a
UV LED, centered at 365 nm, as an excitation source. The Crude Oil sensor has a wide band
pass filter (400-600 nm), which allows detection of a broad range of oils in water, whereas the
CDOM sensor has a narrower band pass filter (470 nm with a band pass of 60 nm) optimized for
the fluorescence of CDOM. These three sensors are mounted equidistant from each other on the
C3 Fluorometer’s optical head which comes standard with a temperature probe.
The C3 Submersible Fluorometer was configured with a mechanical wiper located on the
optical head used to reduce biofouling of the sensors during long term deployments. Opposite
the optical head is the end cap which has a pressure sensor for measuring depth and an 8-pin
stainless steel bulkhead connector that is used for communication and data transfer. The optical
head and the end cap are fastened to a Delrin plastic housing using non-metal fasteners. The C3
Fluorometer is 9.1 inches long and has a diameter of 3.9 inches over the length of the instrument.
The C3 Fluorometer is factory sealed and pressure tested to ensure its operation up to a depth of
600 meters and between -2 and 50 degrees Celsius. C-Soft is Turner Designs’ proprietary
software used to configure, calibrate, communicate with and download data from the C3
Submersible Fluorometer. Each sensor can be custom calibrated using a two point calibration
method. Up to 64,000 data lines may be stored onto the C3’s internal flash memory. The C3
Fluorometer may also be configured to stream real-time digital (ASCII) or analog (voltage) data
to be used for integrating with CTD or third party dataloggers.
SUMMARY of VERIFICATION PROTOCOLS
The protocols used for this performance verification were developed in conference with
ACT personnel, the participating instrument manufacturers and a technical advisory committee.
The protocols were refined through direct discussions between all parties during a Hydrocarbon
Sensor Performance Verification Protocol Workshop held on 2-4 February, 2011 in Moss
Landing, CA. All ACT personnel involved in this Verification were trained on use of
instruments by manufacturer representatives and on standardized water sampling, storage,
analysis and shipping methods during a training workshop held on 18-20 May
,
2011 in Moss
Landing, CA. The manufacturer representative and the ACT Chief Scientist verified that all staff
were trained in both instrument and sample collection protocols.
This performance verification report presents instrument output voltage, relative
florescence units or derived hydrocarbon values reported over time, position, or depth as directly
downloaded from the test instruments or captured through independent dataloggers. The report
includes means, standard deviations, and number of replicates of laboratory determined Diesel
Range Organics, Volatile Hydrocarbons, EEMS, Absorbance, CDOM and Chlorophyll values for
corresponding reference samples at the same time, position, or depth of the instrument
measurements. The report also includes turbidity values for each sample measured on site using
a Hach Turbidimeter which was used for all laboratory and field tests. Instruments were tested
under four different applications, including: (1) laboratory tests with known additions of variance
hydrocarbons; (2) a wave tank test with known additions of crude oil with and without
dispersant; (3) a moored deployment in Baltimore Harbor, and (4) vertical profiling deployments
in the Gulf of Mexico at a site with known leaking bunker oil. A summary of the testing
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