Hi there,
What worked out in the end for me is using an amplifier module coupled with an analog signal isolator. So the ph probe would be connected by BNC to the amplifier, the amplifier connected to the isolator and then the output of the isolator is then taken as the input for your DAQ device. This setup will require a +5V power supply but you can simply use the one from the DAQ device itself.
I used the gravity: analog pH sensor kit
(https://www.dfrobot.com/product-1782.html?srsltid=AfmBOoqxqWSv1BrkzNgGIuCW1xTD0z_xE9lfmJKjGaF3m77kMf...)
and the gravity: analog signal isolator
(https://www.dfrobot.com/product-1621.html?srsltid=AfmBOopUMhOxwj3pZLLaOI1A0AIYLVQou0aXRZUr1YGNIuFdSN...)
for my setup, both from DFROBOT.
Hope this helps you out. Let me know if you need more details 🙂
