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C-FLUOR FAQs

Frequently asked questions about the C-FLUOR Submersible Probes

Updated over a week ago

The range of C-Fluor is 0-100ug/l and the range of Cyclops-7F is 0-500ug/l for chlorophyll in vivo. Why are the C-FLUOR’s range lower than the Cyclops-7F range?

The range for the C-FLUOR is different from the Cyclops-7F for chlorophyll in vivo for a reason. You will rarely see algal concentration in the natural environment reach levels greater than 500 ug/L, so 100 ug/L on the C-FLUOR is plenty. When you get concentrations that high, you certainly don’t need a fluorometer as you can pick up algae with your hands. So, 500 ug/L maximum is extreme unless you’re working with bioreactors or algal farms.

Is the accuracy between the Cyclops-7F sensor and the C-FLUOR sensor different?

The minimum detection for both Cyclops-7F and C-FLUOR sensors are the same. There is no change in accuracy from one probe to the other.

What is the difference between C-FLUOR Chlorophyll blue excitation and C-FLUOR Chlorophyll red excitation for High CDOM? What about Chlorophyll blue excitation for sea water and Chlorophyll red excitation for freshwater?

C-FLUOR chlorophyll Blue excitation is more sensitive to eukaryotic algae such as diatoms, dinoflagellates and green algae which are primary groups found in marine systems. C-FLUOR chlorophyll Red excitation is more sensitive to prokaryotic algae such as Microcystis, anabaena which are primary groups found in freshwaters. However, Blue or Red excitation will detect all algae because all algae contain chlorophyll and the excitation energy from either probe is absorbed and cause the chlorophyll molecule to fluoresce. The benefit of Red excitation is that it is not affected by CDOM rich environments whereas the blue excitation probe will be highly affected by CDOM rich environments. I recommend red excitation for CDOM rich environments unless the customer is looking at less than 0.5 ug/L concentrations, which isn’t typical of any environment unless you’re working in the open ocean where concentrations are less than 0.05 ug/L.

What is the Maximum pressure the C-FLUOR in line adaptor can withstand?

The C-FLUOR in-line adaptor PN 2820-530 can be used up to 100 PSI. The C-FLUOR can handle far more pressure than the adaptor since it is rated up to 2000 m depth.

Temperature Compensation for a C-FLUOR. What is a Zero Point?

Your zero point for C-FLUOR temperature compensation would be whatever temperature you calibrated at. If you were at 20 °C, then you would have the +/- 1.4 % per degree from that starting point. Most times you wouldn’t be working in a range higher than +/- 7°C especially if your application is putting a sensor in a water ecosystem. This would work well for controlled lab settings with a consistent concentration, but out in the field, there are too many variables that would contribute to a change in concentration that it would be difficult to warrant calculating this.

I have water inside the Cyclops-7F or C-FLUOR can I still get it repaired under warranty?

Warranty is void if water is inside from usage of the Cyclops-7F or C-FLUOR. Exception to that would be if the unit was used directly out of box and it leaked.

Can I do calibrations in a clear beaker for the Cyclops-7F, C-FLUOR, or C3, and C6p?

We recommend reading our submersible instruments like the Cyclops-7F, C-FLUOR, or C3 and C6P in a darkened beaker or beaker wrapped in black electrical tape. There must be at least 3 inches from the face of the probe from the bottom of the beaker for best results.

Do you have any application note of the interference that Turbidity and the Fe can cause in the chlorophyll measurement?

The Cyclops-7F and C-FLUOR have the same optical configuration so the interferences would be similar, but not exactly the same. This is something the customer must determine for their water system. In our experience, very high turbidity and Fe concentrations will interfere with almost any optical measurement simply due to light blocking interactions, but we are unable to say to what degree.

What is the type of glass used on the C-FLUOR submersible probes?

We build the C-FLUOR with sapphire optical windows for greater protection from the elements and clarity with sampling.

What is the minimum volume needed for C-FLUOR to analyze from. I propose to add concentrations of differing dyes to each source at the same time, and then monitor samples in the bore over several months post 'injection' to determine if the dye/s are detected in the bore samples or not. Another is to sample fortnightly using a snap sampler, so the sample from the bore for analysis may be limited to 250m1.

Either of these methods are fine, there isn’t a set minimum volume that the C-Fluor can read. However, you will have to account for the optical angle at which the sensor reads best at which is more than 3 inches of space from the bottom of a container, if no container is involved, this is not an issue. You should account for max flow of liquid running through it. If you are attempting to take, say 50 data points for 10L of water, but you have a high flow rate, the flow will blast right past. You’d probably and realistically get 1 data point. It’s best to slow that flow down if you want more datapoints.

Can I use a single C-FLUOR configuration to differentiate between 5 different dyes?

C-Fluors are specialized to read for their specific applications of which, the available parameters are available on our product datasheet. S-0244.pdf Rhodamine and Fluorescein dye are the two that work with the C-Fluor, but you will need one sensor for each dye you are using.
Examples of other dyes we get asked often:

  • Lissamine FF (green) – Does not work

  • Amino G acid (blue) – Does not work

  • Eosine – Does not work

Can I use the C-FLUOR Rhodamine application to read for sulforhodamine B or rhodamine B?

Our C-FLUOR instruments can read for sulforhodamine B or rhodamine B, but with limited capacity. We do not have testing limits as we calibrate our sensors and input in filters that operate in wavelengths for Rhodamine WT that may overlap with rhodamine B or sulforhodamine B. I would recommend the use of Rhodamine WT as a better dye alternative.

Rhodamine WT was developed to overcome a disadvantage of rhodamine B, which was the adsorption on suspended sediment. The same modification was also expected to reduce toxicity, and limited testing confirmed this. Additionally, fluorescent yield of Sulphorhodamine B is not as good as Rhodamine RWT and B. http://docs.turnerdesigns.com/t2/doc/appnotes/998-5000.pdf

How can I monitor Algal Growth in 25mm test tubes using the C-FLUOR?

Please view the technical note here for an example setup with the C-FLUOR and algal growth in 25 mm test tubes.

When should I use my C-FLUOR shade cap?

We recommend use of the C-FLUOR shade cap as it provides a fixed distance for sample measurement and minimizes affects from ambient light. The Shade Cap also offers protection for the optics and prevents damage from deploying, recovering, or transporting the instrument, in fast-flowing environments, and/or from bottoming out in shallow environments.

How can I power and collect data from analog C-FLUOR?

Our Analog C-FLUOR probes are analog output fluorometers that output voltage only, data can be collected via any datalogger that accepts a 0-5 volt analog signal.

Our DataBank Handheld Datalogger and any 3rd party datalogger capable of accepting 0-5 Volt is compatible with the C-FLUOR. This makes for easy data collection in the field. C-FLUOR probes can be powered using any 3-15 volt power source. Analog C-FLUOR sensors can output measurements as long as there is power supplied. The datalogger used in conjunction with the C-FLUOR will ultimately, provide a bottleneck for low sampling rates. Keep in mind that the sampling rate set on the datalogger cannot exceed the limitations of the C-FLUOR which has a sampling rate at half a second.

Can C-FLUOR be integrated into CTDs, ROVs, or AUVs?

Yes, C-FLUOR can be integrated with any AUV, ROV or system that will accept a 0 to 5 VDC analog input and has a maximum depth rating of 2000 meters. View our user's manual for more information on C-FLUOR probes.

What preventative maintenance or care should always be done before deploying my C-FLUOR?

Here are some examples of preventative care before deploying the C-FLUOR:

  • To protect your bulkhead connector from damage, a light coat of Silicone spray should be used on the rubber of the male pins of the bulkhead to aid in sealing. The manufacturer recommends 3M™ Silicone Lubricant Spray or Loctite 8021 spray.

  • Note: You should avoid using silicone grease. DO NOT USE WD-40 - it will destroy the connectors.

What turbidity standards should I use for the C-FLUOR?

AMCO/GFS has turbidity standards for use with the C-FLUOR. Standards can be purchased directly from GFS Chemicals utilizing the information found on our calibration standards article: Calibration Solutions for Various Instruments | Turner Designs Help Center

If I want to tow C-FLUOR through a Rhodamine plume, how fast will the sensor respond? What is the instrument response time?

If power is supplied to the C-FLUOR continually while towed, the data output rate for analog data output is <0.6 seconds.

How does the blue green algae C-FLUOR sensor or the chlorophyll in vivo C-FLUOR sensor eliminate the influence of turbidity?

The C-FLUOR uses high quality interference filters to eliminate light scatter which may be read as turbidity.

At what distance from the end of the C-FLUOR sensor is the measurement taken?

The C-FLUOR can detect materials as far away as 3 inches from the sensor head, which is why Turner Designs recommends at least a 3 inch (7.62 cm) clearance from the optical head when taking measurements. An exception to this would be if you are using the shade cap, as the shade cap is designed as an optical “backstop” for the sensor. Check out our article explaining best practices for the submersible instruments: Submersible Fluorometer Best Measurement Practices | Turner Designs Help Center

What angle does the C-FLUOR need to be to take a measurement?

More information on the angle the C-FLUOR needs to be to take a measurement is talked in length with our article here: Submersible Fluorometer Best Measurement Practices | Turner Designs Help Center. In general, keeping the instrument as close to vertical as possible is recommended.

How much liquid will the C-FLUOR flowthrough cap hold?

The C-FLUOR flowthrough cap will hold 5 mL of fluid.

Where can I find instructions on how to install the C-FLUOR Flow Through Cap?

Instructions for the C-FLUOR Flow through cap are available here: http://docs.turnerdesigns.com/t2/doc/instructions/998-2120.pdf

Where can I find information about C-FLUOR cables?

Please refer to the C-Fluor cable guide provided here: Cable Guide.

What is the volume (size) of the area (or the control volume) that C-FLUOR takes the reading from?

We recommend at least a volume of 38 cubic inches for C-FLUOR readings or calibration to assure that light interference is minimized.

Where can I find information about the C-FLUOR optical specifications for the applications?

For more information about the C-FLUOR optical specifications, please refer to the Optical Specification Guide. Alternatively, you may ask information to our bot for quick answers.

Does the Analog C-FLUORs have the ability to be plugged into a computer?

Analog C-FLUOR units output 0-5 volt signal proportional to the fluorescence detected. These probes cannot be connected directly to the computer, they must be connected to a datalogger that will accept 0-5 volt signal.

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