We have a handy article that goes over all of the details needed to get a C3 or C6p for the first time. This is in conjunction with the user manuals we have written for the C3 and C6p.
C3 and C6p User Manual: 998-2300.pdf
C3 and C6p C-SOFT Troubleshooting Manual: C3 or C6p Troubleshooting and Setup | Turner Designs Help Center
C3 and C6p Best Measurement Practices: Submersible Fluorometer Best Measurement Practices | Turner Designs Help Center
C-Soft Software Download: Software & Firmware | C6P Submersible Fluorometer | Turner Designs
Cable Guide for C3 or C6p: This is a guide to the C3 cables and their uses
Calibration solutions for C3 or C6p: Calibration Solutions for Various Instruments | Turner Designs Help Center
Background Information
The C3™ and C6P™ Submersible Fluorometers can be configured with up to three or six optical sensors, respectively, spanning from deep ultraviolet to infrared. Internal memory storage capacity combined with an external submersible lithium ion battery allow the C3 or C6P to run during extended or short-term deployments. Each unit comes with a factory-installed temperature sensor. Factory-installed depth sensors and copper-armed mechanical wipers are also available. The durable delrin housing is highly resistant to harsh environments. An antifouling copper plate is available as an option for longer deployments.
The Integrator Firmware option is recommended when the C3 or C6P is used as part of a continuous sampling system that requires 24/7 streaming data collection.
C-Soft Windows™ based software allows for intuitive calibration, datalogging set-up and file management capabilities as well as data integration.
Getting Started with Understanding the C3 or C6P model
The C3 or C6p can be used in one of three modes:
Uncalibrated - Raw Fluorescence Mode
Values in the Raw Fluorescence Mode are referred to as “Relative Fluorescence Units” (RFU). It is important to note that these values are not blank subtracted or scaled to a standard. They are relative values.
Uncalibrated - Raw Fluorescence Blank Subtracted Mode
Values in the Raw Fluorescence Blank Subtracted Mode are noted as RFUB. These values are blank subtracted to account for background fluorescence that may be present in the sampling conditions but are not scaled to a standard. They are relative values.
Direct Concentration Mode
Values reported in the Direct Concentration Mode are blank subtracted and scaled to a standard solution that has a predetermined standard value. This article will provide steps to ensure values are reported as Blank Subtracted Concentrations in your units of choice.
The equation used to calculate concentrations after calibrating to Direct Concentration Mode is:
A digital voltmeter or multimeter can also be used to save an external calibration for the C3 or C6p using pigtail cable setup.
The Setup Steps for an example Calibration:
Materials Required:
This is an example using a C3 or C6P that has rhodamine optics. The instructions below will be very similar to the other sensors that can be installed on the instrument.
C3 with included PN 2200-150 (programming cable), PN 2300-115 (integration cable), and PN 159-0191 (12V power supply).
Computer with C-SOFT software.
Two large containers
We recommend using a 1-2 Liter sized black electrical covered beaker or equivalent container if using a C3. This allows for the sensor face to be submerged with more than 3 inches above the bottom of the container and more than 2 inches clearance between the circumference of the sensor and the inside surface of the container.
Containers should not be used of general plastic as that can have fluorescent properties. A bucket is sufficient if available.
Alternatively, if you have our optional shade cap accessory such as PN 2300-500 for the C3, the container type can be ignored. A smaller volume container can be used, as long as the shade cap and sensor face can be submerged fully with no air bubbles.
Also alternatively, a flowcap with plugs on the ends to hold the liquid.
Deionized or ultrapure water
Rhodamine Calibration Standard
We are using a 100 ppb calibration solution as an example
Calibration of the C3 or C6p
C-SOFT Setup
This presentation assumes that you have installed the USB cable and C-SOFT Software onto a computer. C-SOFT Software is available on the Turner Designs Website. Software & Firmware | C3 Submersible Fluorometer | Turner Designs Refer to our other help guide on getting the software setup: C3 or C6p Troubleshooting and Setup with C-SOFT | Turner Designs Help Center
Ensure everything is unplugged.
Plug only the communication cable to the computer to see if computer can recognize the cable in device manager. (Cable looks like the first two images but combined: This is a guide to the C3 cables and their uses (turnerdesigns.com))
Plug C6P/C3 to communication cable.
Then plug power supply to the communication cable connected to the C3/ C6p.
Watch for C6P/C3 to flash a light from the sensor and see if it shuts off.
(UV sensors are best seen with a piece of blank white paper held in front)Unplug power supply from communication cable.
Run C-SOFT.
Plug in power to C3/C6P
See if C-SOFT initializes after 10 minutes. (on instruments with lots of saved data, it can take an hour). The connection icon, located on the upper right of the screen, will turn green if connected. If the connection icon does not turn green, disconnect and reconnect power.
Screen when connected will appear like this image below
Select Current Data Tab to ensure C3/C6p lights come on and data is streaming.
Confirm the C3 or C6p sensor is connected properly and powered by checking to see that the LED is illuminated.
If using a PTSA, Crude Oil, Refined Fuels, FDOM, Optical Brighteners, or Tryptophan C3 or C6p sensor with a UV LED, avoid looking directly at the sensor’s optical face to protect your eyes. Instead, hold a white sheet of paper in front; if it shows blue light, the UV LED is working properly.
Example images of a rhodamine sensor and a UV sensor:
Click the Calibrate button on the right side tab of the desired sensor you would like to calibrate. This example we selected Rhodamine.
A new tab will appear that should appear similar to this image below
Calibration setup: Fill your container with deionized or ultrapure water
Fill the container full enough that there are more than 3 inches of water from the bottom. This will ensure that you are able to completely submerge the optical face of the sensor and still have the recommended 3 inches of water above the bottom of the container. If you are using the shade cap you want to be sure that there is enough water to fully submerge the shade cap as well as the optical face of the sensor.
Example image of a clear beaker below for clarity and the recommended for calibration - darkened beaker fully filled to the brim:
Alternatively, you can use a bucket if the C3 or C6p has a shade cap installed.
Another alternative is to use a flow cap. A plug must be utilized to prevent the liquid from exiting the ports and the top portion must be placed above to prevent ambient light from entering.
Fill another container with the Calibration Standard and set aside. This container should also be filled with roughly the same volume of standard as the blank container.
Ensure inserting the sensor into the container is done at an angle and then straightened up to prevent air bubbles from being trapped.
Wait until “Current RFU” readings have stabilized then select the “Set Blank” button to set the blank value. The Current RFU may jump if air bubbles are still trapped. If removed, it takes 5-10 seconds to stabilize around a certain point. C-SOFT software will begin recording the values for the blank around the three gains.
After finishing with the blank, insert the C3 or C6p into the calibration solution.
Enter the concentration value of your standard solution in the Enter Standard Value box. In our example, we have 100 ppb of Rhodamine. Select the “Units” button to set the unit value. When ready, press "Set Standard" button so the Software will start measuring the RFU signal received from the sensors.
You may notice that Step 4 as shown in the C-SOFT calibration indicates temperature compensation. This is to be selected only for chlorophyll or rhodamine.
Click “Save Calibration” button to save the current work you ran for this instrument.
When you have finished with calibrating the C3 or C6p select View Calibration Data to view the data and save or print for your own records. It will pop up as a tab on a browser to view. You may also watch the Data Table of the current data streaming as the sensors read the calibration solutions.
The C3 or C6p is now calibrated and you may begin measuring samples. Values will be reported in units you set that are blank subtracted and scaled to a standard solution that was used for calibration.