I’ve made an Arduino library for communicating with the Yosemitech sensors: https://github.com/EnviroDIY/YosemitechModbus
It’s built on top of my modbus library: https://github.com/EnviroDIY/SensorModbusMaster
In the modbus library there’s a hardware folder with the plans for a little “wing” board to more easily connect a Yosemitech sensor to a Mayfly.
I can’t actually say very much about the data quality, though. The probe Anthony mentioned ended up bounced between desks for over a year before I got the library to communicate with it working. When we ran a calibration on it after that, it didn’t seem as stable as the YSI sondes we have. Since the sensing cap only has a listed life of a year, we couldn’t really say if that was because the sensor wasn’t as good or the cap was just too old. And we still didn’t have a good case set up to actually put it anywhere, so it just sat on a desk for several more months. About a month ago I attached it to a group of Yosemitech sensors I have running downstairs in one of our artificial flumes. We are running those sensors to watch how the turbidity compares, but I threw the DO probe on because it was looking lonely on my desk. If you want to look at the data from it: https://data.envirodiy.org/sites/SWRCWetLab/