ARDUNIO PH and Salinity probes?

[GuppyHJD]

Hello,
I have an arduino (actually ESP8266-12E) that is monitoring my sump water level, temperature and controlling three dosing pumps.
I have used two different pH probes that have proved unreliable.
Is there a pH probe that you recommend?
Is there a salinity probe that would work well with an Arduino board?

Thank you

 

[DaJMasta]

Have you used the atlas scientific modules? They have just an analog interface, but they've also got an integrated digital interface that can handle calibration and compensation and ends up being a pretty small package.

It's also worth mentioning that pH probe readings are pretty susceptible to EMI and grounding issues, so the better implementations I've seen for them have the pH probe's ground isolated from the main system ground. Perhaps an isolation scheme could give you better results with the circuits you've tried before. Otherwise, the probes themselves should be largely interchangeable, maybe a storage or cleanliness reason is to blame?

 

[Ranjib]

anything with galvanic isolation will do. use atlas scientific (sensor+isolated carrier board ), they have ready made python library to read the sensor. if you can implement the reef-pi i2c protocol, the opensource ph module will also do the job (i think rob sells it independently of robo tank, but verify) , it will cost little less.