Turbidity Sensor Information/Questions

There’s a few things in your post to clarify to make sure we’re talking about the same equipment.  The various instructional videos and manuals we’ve released in the past few years

There’s a few things in your post to clarify to make sure we’re talking about the same equipment.  The various instructional videos and manuals we’ve released in the past few years cover several different configurations of sensors and cables and equipment.  The majority of the stations we deployed before 2020 had a Meter Group CTD sensor and a Campbell Scientific OBS3+ turbidity sensor on them.  We also used to sell Monitoring Station Kits that contained Pelican 1120 cases that were pre-drilled and tapped for 3 cable glands:  one for solar panel cable, one for CTD sensor, and one for OBS3+ turbidity sensor.  The CTD and old turbidity sensors had cables that required the same diameter cable glands, so we used the 69915K53 size (0.24″-0.47″ cables and 1/2″ NPT threads).

Campbell Scientific discontinued the OBS3+ turbidity sensor a few years ago and since there was not a ready replacement, we stopped including the cable gland and pre-drilling the holes in the Pelican cases that we sold, since most people were just building CTD-only stations.

A few months ago, Campbell Scientific released the ClariVUE10 turbidity sensor, and it has a cable with a smaller diameter.  Therefore we recommend using a 69915K54 cable gland (0.2″-0.35″ range, 1/2″ NPT) for the ClariVUE10 turbidity sensor cable.

The Meter Group Hydros21 sensor can be purchased with either bare wire leads on the end of the cable, or a 3.5mm stereo headphone plug.  We usually tell users to choose the stereo plug because it’s the easiest to use, and we developed a Grove-to-3.5mm-jack adapter board many years ago for connecting the stereo plug to the Grove jack of the EnviroDIY Mayfly.  The ClariVUE turbidity sensor cable has bare wires on the end, there is no connecter on the cable. We developed the multipurpose 6-pin screw terminal board for using bare wire sensors like the ClariVUE with the Mayfly.  You could also use that same screw terminal board for connecting a Hydros21 CTD sensor to the Mayfly if you bought the sensor with bare wires instead of the headphone jack.  It’s worth noting however that we may need to develop a new screw terminal board with some additional circuitry on it to properly communicate with some SDI-12 sensors like the ClariVUE10, so we’re still working on this, which is why we haven’t published official instructions on how to connect a ClariVUE10 to the Mayfly yet.

The term “Molex connectors” refers to a wide variety of sizes and types of connectors so I’m not sure to which ones you’re referring, but  there aren’t any Molex connectors anywhere on the EnviroDIY Mayfly, and we don’t use them in any of our recommended instructions.  Are you referring to the Grove cables and Grove jacks (the six or seven white, 4-pin polarized sockets on the Mayfly)?  All you should need to connect a ClariVUE10 to the Mayfly is the screw terminal board mentioned above, and a short double-ended Grove cable, like the ones we include in the Starter Kit or the Monitoring Station Kit, or that can be found from various sellers on Amazon.

Another thing to note, the ClariVUE10 sensors require 9.6v to 18v DC to operate.  The previous EnviroDIY Mayfly boards we sold prior to the fall of 2021 were not capable of powering these sensors.  The Mayfly v1.0 we released in October and the new v1.1 board releasing next week are able to generate a 12v power source capable of powering the sensor, but you have to move the small jumper next to the Grove jack to change the voltage level sent to that jack to match whatever sensor you’re connecting (your options are 3.3v, 5v, and 12v).  So instruction for all these steps are being finalized now, along with writing and testing new code examples for all the major configurations we recommend, which will include the ClariVUE10.

As for the anti-fouling tape, it’s probably not necessary.  The ClariVUE10 is manufactured with a copper end-plate, so algal growth right around the sensor window should probably be reduced, however the sapphire windows themselves will need to be cleaned regularly, plus we find that the majority of fouling issued to our turbidity sensors is cause by large debris like leaves, sticks, mud, rocks, etc, which is why still suggest frequent service visits to the station, especially for stations that don’t transmit their data to an online portal like Monitor My Watershed.

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Given the popularity, complexity, and expense of turbidity sensors, the team here at the Stroud Center has compiled a snapshot of some commercially-available options that may help people decide on the

Given the popularity, complexity, and expense of turbidity sensors, the team here at the Stroud Center has compiled a snapshot of some commercially-available options that may help people decide on the best option. This table likely excludes many vendors and models, and it only summarizes sensors that we have recently used or investigated. In addition to these commercially-available options, you might consider do-it-yourself options like OpenOBS, a well-document project on Github with a peer-reviewed background. Another open-source DIY turbidity sensor is described by Droujko and Molnar 2022 in Nature, Scientific Reports.

• Campbell Scientific Clari-Vue (recently replaced the OBS3)
  • no wiper
  • pre-calibrated
  • SDI-12 at 5V
  • 9.6-18V (nominally 12V)
  • compatible with Mayfly version 1.1 (or any Mayfly version with an interface board with separate 12V supply)
  • compatible with Modular Sensors
  • $$ on a scale of $ (<$1000), $$ ($1000 – $2000), and $$$ (>$2000)
• Yosemitech Y511-A
  • includes wiper (the Yosemitech Y510-B does not include a wiper)
  • pre-calibrated
  • Modbus over RS485
  • 5-12V (nominally 12V)
  • compatible with Mayfly version 1.1 with EnviroDIY RS485 adapter (or any Mayfly with both separate 12V power supply and RS485 adapter)
  • compatible with Modular Sensors library
  • $
• Turner Designs Turbidity Plus
  • available with and without wiper
  • not pre-calibrated
  • analog voltage communication
  • 3-15V
  • compatible with Mayfly version 1.1 with multi-purpose 6 pin screw terminal grove adapter (or any Mayfly with a voltage divider with separate 12V power supply)
  • not compatible with Modular Sensors library
  • $$
• Turner Designs Cyclops 7
  • no wiper, but has an optional cap to protect the sensor window
  • not pre-calibrated
  • analog voltage communication
  • 3-15V
  • compatible with any Mayfly version with multi-purpose 6 pin screw terminal grove adapter
  • compatible with Modular Sensors library
  • $$
• Analite NEP-5000
  • includes wiper
  • pre-calibrated
  • SDI-12 or Modbus over RS485 or analog communication
  • 8-30V
  • compatible with Mayfly version 1.1 (additional adapters required depending on communication protocol used)
  • not compatible with Modular Sensors library
  • $$$

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Hello, I have a few Mayfly dataloggers deployed with Campbell Scientific OBS3+ sensors. I recently purchased a Campbell Scientific ClariVUE10 sensor and a Mayfly 1.1 datalogger and am looking for some

Hello, I have a few Mayfly dataloggers deployed with Campbell Scientific OBS3+ sensors. I recently purchased a Campbell Scientific ClariVUE10 sensor and a Mayfly 1.1 datalogger and am looking for some advice.  I noticed that the new ClariVUE10 has only 4 wires (OBS 3+ has 6). Can I use the EnviroDIY Multipurpose 6-pin screw terminal to attach the new sensor to the board or do I need to purchase something else?

If I can use the 6-pin, which wires plug into which screw terminals? White is SDI-12 data, red is 12V power, clear is shield and black is ground.

Thanks!

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The old Campbell OBS3 turbidity sensor was an analog-output sensor that had 2 separate voltage outputs, one 5v power supply wire, and 3 ground wires, which is why I designed the old version of the 6-p

The old Campbell OBS3 turbidity sensor was an analog-output sensor that had 2 separate voltage outputs, one 5v power supply wire, and 3 ground wires, which is why I designed the old version of the 6-pin screw terminal board that way, because we primarily used it with the OBS3 sensors and connected it to one of the Aux Analog Grove jacks on the Mayfly board.

The Campbell ClariVUE10 sensor is a digital-output sensor that uses SDI-12 protocol and only has one signal output and 2 ground wires (plus the one 12v power wire).   And because we wanted a new screw terminal board that gave people the option of also combining signal pins (for hooking two SDI-12 sensors to one board) or adding resistor dividers for analog sensors, I designed the new multi-purpose screw terminal board to replace the old version and give users the option of configuring the board for different types of sensors.

In your case, you are able to use the old style screw terminal board with your Mayfly v1.1 board and a ClariVUE 10 sensor if you connect the wires as follows:

• Black wire (ground) and clear wire (shield) to any of the screw terminal board’s GND pins
• Red wire (12v power) to the screw terminal board’s VCC pin
• White wire (SDI-12 data) to the screw terminal board’s D2 pin

Then you’ll need to connect the Grove cable from the screw terminal board to either of the two Grove sockets in the center of the Mayfly (the one’s labeled D4-7  SDI-12).  You’ll also want to make sure you move the little jumper block next to that one socket from the default 3v position to the 12v position.  Once that is connected and the switched power (D22) is set high so that the sensor is powered, you can communicate with it through the D7 pin.  The sensor ships from the factory with the default SDI-12 address of “0”, so you might want to change it to something else if you don’t want it to conflict with any other SDI-12 sensors you connect to the Mayfly at the same time.  If you want to use a Hydros21 CTD sensor along with the ClariVUE10, connect the Hydros21 to the Mayfly’s other SDI-12 Grove jack and keep that one at the default 3v jumper position (we’ve found that the Hydros21 sensors work best at 3v), but you’ll have to change the Hydros21 channel number to something other than its default “0” channel, otherwise it doesn’t respond properly to measurement commands.  We typically use “1” for the CTD channel and “2” for the turbidity channel.  We haven’t published an example sketch of using a ClariVUE10 sensor yet because we’re finalizing our testing of various configurations with the new sensors, but I’m hoping to publish that example next week on Github.

Readers should note that the Mayfly v1.1 boards are the only ones capable of powering a ClariVUE10 turbidity sensor directly from the Mayfly board.  Older Mayfly boards (v1.0 and earlier) will need a separate 12v boost adapter (coming soon) or a separate 12v power source to power the sensor directly since the older Mayfly board don’t have the ability to generate the proper power for the ClariVUE sensors.

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Thank you for the response Shannon. I stripped and tinned the wires on the sensor, connected it to the 6-pin screw terminal as directed, connected the screw terminal with a grove cable to a SD-12 port

Thank you for the response Shannon. I stripped and tinned the wires on the sensor, connected it to the 6-pin screw terminal as directed, connected the screw terminal with a grove cable to a SD-12 port on a Mayfly 1.1 board with the jumper moved to the 12v position. I also changed the sensor address to “2”.   For some reason, I am getting an error reading of -9999, which I think means that my sensor isn’t getting power. I used the code in the menu a la carte example on github. I think the D22 pin is set to high in that example. Does anyone know what  I could be doing wrong?

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I used the Mayfly 1.1 board and the sketch below. Thank you for helping me!

I used the Mayfly 1.1 board and the sketch below. Thank you for helping me!

 

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I uploaded the “SDI12/b_address_change” sketch and the address of the sensor is correctly assigned at “2”. My sketch is below. I modified the DWRI CitSci code for the ClariVUE. Thanks

I uploaded the “SDI12/b_address_change” sketch and the address of the sensor is correctly assigned at “2”. My sketch is below. I modified the DWRI CitSci code for the ClariVUE. Thanks for taking a look!

 

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Thanks for posting your code, I edited your post to put it into the “code formatting” window that you can use when pasting code into our forum.  It’s the little unlabled icon that l

Thanks for posting your code, I edited your post to put it into the “code formatting” window that you can use when pasting code into our forum.  It’s the little unlabled icon that looks like this:  “<>” in the toolbar above the text entry box.

Your issue is caused by an error on line 186.  It should look like this:

 

You can also include another variable to report the Clarivue temperature (because the sensor also reports water temperature) by adding this line to your variable list:

I haven’t published the official example code for using a ClariVUE10 sensor yet because they haven’t added the sensor to the list of supported sensors on the MonitorMyWatershed website.  Once it gets added to MMW, I will publish the example, but it’s essentially exactly what you have above, minus the ES2 sensor, and with the correct variable declaration that I just posted here.

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