The Cyclops-7F blue excitation version may be best for your needs if you are working in high turbid water conditions, but it is affected by CDOM. Alternatively, Cyclops-7F red excitation is able to ignore CDOM completely but will be affected by high turbid conditions. If you are able to prioritize which of these problems would be in your water system, one or the other would work. Otherwise, if your area has both turbidity and CDOM issues, both sensors could be used in tandem since they can see the same concentration of chlorophyll. You would just need to create some offsets of the variation between the two.

In terms of reading CDOM and correlating it to Chlorophyll a, Cyclops-7F blue excitation would act like a CDOM sensor in the presence of CDOM since it can respond linearly. If instead you would like a CDOM and blue excitation sensor to work together, all you would need to do is create an offset since both datasets would be linear.
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Cyclops-7F Red excitation works best in the bay and freshwater. The sensitivity of 0.3 ug/L is responsive enough to the algal species typically found in those water systems. It would be worse suited for the ocean environment since the Minimum detection limit is so high. It does not see CDOM at all, just chlorophyll. Which won’t really be a factor in the ocean since CDOM and cyanobacteria are not found in high abundance in that water system. Cyclops-7F Blue excitation is great for the ocean. It has a low minimum detection limit at 0.03 ug/L and you will find for that reason it operates best in ocean environments. It can reject turbidity a lot better than red, but not by much. This is entirely due to the way the instrument is built and the wavelength it operates at.
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Clean the Cyclops-7F as often as you like, use clean tap water or deionized water to rinse off the sensors. It all depends on how long it is out in the field and the conditions present in the water system. See what works for your needs. If there is something like a barnacle growing on it, use soap and water. If you have to use an abrasive, I suggest the yellow side of a Brillo pad like sponge, not the rough green side or a soft bristle toothbrush.
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The Cyclops-7F resolution would be a 12 bit ADC logger. It wasn’t meant for highly analytical work or detailed data logging events or high-resolution studies. If we did mean for it to do any of those things, we wouldn’t configure it for 12 bit, it would be a 24 bit logger.

As the autogain on the Cyclops-7F increases, the sensitivity increases and the concentration range decreases. Our optical specification guide available on our website also lists the limits at which they can read at, example: linear range of 0-1000 ppb for Rhodamine. Keep in mind that this gain switching does take seconds to readjust.

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

The Cyclops-7F and C-FLUOR have the same optical configuration so the interferences from iron would be similar, but not the same. This is something the customer must determine for their water system. I can say that very high turbidity and Fe concentrations will interfere with almost any optical measurement simply due to light blocking interactions, but I can’t say to what degree.

Cyclops-7F can only perform to the minimum 1 reading/second, and C-FLUORs can perform 1 reading/half a second. In terms of why this limitation exists, it was not designed for faster or slower readings, just for 1 reading per second or 1 Hz readings only.
These units are for use in water and in environmental conditions, many individuals who use our products aren’t looking for utilities of sub seconds readings mainly since it is for monitoring purposes. It is highly likely that the environmental conditions will affect the readings, but it should not differ greatly between seconds.

While the sensor may have an increased signal when reading chlorophyll in leaves, its intended purpose is to be in vivo or applications with submersion in a liquid.

Here are some examples of preventative care before deploying the Cyclops-7F:

For more information about the C-FLUOR optical specifications, please refer to the 998-2181.pdf. Alternatively, you may ask information to our bot for quick answers.

The Cyclops-7F flowthrough cap PN 2100-600 can be used up to 50 PSI. The Cyclops-7F can handle far more pressure than the adaptor since it is rated up to 600 m depth.

Your zero point for Cyclops-7F 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.

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.

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.

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.
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We build the Cyclops-7F with epoxy optical windows for greater protection from the elements and clarity with sampling.

Either of these methods are fine, there isn’t a set minimum volume that the Cyclops-7F 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.

Cyclops-7F are specialized to read for their specific applications of which, the available parameters are available on our product datasheet. S-0209.pdf Rhodamine and Fluorescein dye are the two that work with the Cyclops-7F, but you will need one sensor for each dye you are using.
Examples of other dyes we get asked often:

Our Cyclops-7F 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.
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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

We recommend use of the Cyclops-7F 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.

Our Cyclops-7F are analog output fluorometers that output voltage only, data can be collected via any datalogger that accepts a 0-5 volt analog signal.
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Our DataBank Handheld Datalogger and any 3rd party datalogger capable of accepting 0-5 Volt is compatible with the Cyclops-7F. This makes for easy data collection in the field. Cyclops-7F probes can be powered using any 3-15 volt power source. The Cyclops-7F sensors can output measurements as long as there is power supplied. The datalogger used in conjunction with the Cyclops-7F 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 Cyclops-7F which has a sampling rate at half a second.

Yes, Cyclops-7F 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 600 meters. View our 998-2100 Rev 4.0 for more information on Cyclops-7F probes.

Here are some examples of preventative care before deploying the Cyclops-7F:

AMCO/GFS has turbidity standards for use with the Cyclops-7F. 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 power is supplied to the Cyclops-7F continually while towed, the data output rate for analog data output is 1 second.
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The Cyclops-7F uses high quality interference filters to eliminate light scatter which may be read as turbidity.

The Cyclops-7F 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
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Two things that can dramatically influence the calibration of any of our submersible probes are a reflective surface that is under the glass beaker and micro-bubbles on the optic surface of the sensor. A measurement in DI water that is < 200 mV is still ok to use as a blank. A 200mV measurement would still represent less than 4% of the high scale. The Cyclops-7F should always be more than 3" away from the bottom of the beaker. You should not try to calibrate in a beaker with a diameter less than 5", unless you are calibrating with the shade cap on the Cyclops. The shade cap is designed as an optical “backstop” for the sensor and can be used in a smaller volume of water.

More information on the angle the Cyclops-7F 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.

The Cyclops-7F flowthrough cap will hold 5 mL of fluid.

Instructions for the Cyclops-7F Flow through cap are available here: http://docs.turnerdesigns.com/t2/doc/instructions/998-2120.pdf

Please refer to the Cyclops-7F cable guide provided here: Formatting Instructions.

We recommend at least a volume of 38 cubic inches for Cyclops-7F readings or calibration to assure that light interference is minimized.

All Cyclops sensors have a desiccant pack that has small beads inside of it to prevent moisture from affecting the electronics. If you shake the Cyclops gently you can hear those tiny beads rattling in the pack. Please refer to the picture below:

The x100 gain on the Cyclops-7F is best for use with low concentrations. For example, a 2 ppb concentration of Rhodamine WT will generate in the neighborhood of 1.3V in the x100. The entire range for the x100 scale is only 0-10ppb. This gives you 10 times better resolution than the medium scale and 100 times more resolution than the x1 scale. In the x100 scale, each mV is going to signify an incredibly small change in actual concentration. Keeping this in mind, it is typical to see micro noise in the x100 gain.

We recommend using 1-5 naphthalenedisulfonic acid disodium salt as a lab standard for the refined fuel sensors. Please refer to the application note on Detection of Refined Oils (Fuels) in Water: S-0113.pdf

1-5 naphthalenedisulfonic acid disodium salt can be purchased from: Sigma-Aldrich

Website: MilliporeSigma | Life Science Products & Service Solutions

In order to prepare a standard, weigh out some of the standard (grams) and dissolve in a known volume of water (milliliters). Now you have a concentration of grams/milliliter. From there you can convert to micrograms/liter or ppb.

Automatic gain control for the Cyclops can be controlled in various ways. If the Distributed Control Switch has logic controlled relay system it can be controlled as illustrated in the picture below. It is important to note that both legs of the relay should not be closed at the same time.

Another option would be to integrate an analog multiplexer to handle the gain switching. Below is a link to some of the common HC4052 datasheets. http://www.alldatasheet.com/view.jsp?Searchword=HC4052

If you are using a Cyclops with our Cyclops Explorer, refer to our guide on this: Cyclops calibration for Rhodamine WT with the Cyclops Explorer
As of 2023, we no longer offer the Cyclops Explorer for sale and are unable to assist with repairs due to material obsolescence.

We recommend reading our article to get the Cyclops calibrated with the DataBank Datalogger: How do I use the DataBank Datalogger to calibrate the Cyclops-7F, C-FLUOR, or C-Sense? | Turner Designs Help Center or our older article: Microsoft PowerPoint - S-0173.pptx