Do I need to isolate arduino sensors?

Question

Arduino

Good afternoon!
I want to have the arduino measure the ph and tds of a solution using two submersible sensors. As I understood from the Internet, they can give each other some kind of tips and interfere with each other, but I did not find more specific information. Can you tell me what kind of problems you might run into here?

Answer 1

here the word sealing is more suitable - because the solution getting on the metal parts will lead to corrosion and, in the long term, to the destruction of the circuit.
if the circuit / wires are in contact with the solution, then not only mutual interference will appear, but also leaks, which will also introduce an error in the measurements.
fill with varnish / sealant, which will definitely be resistant to your solution.
it is quite easy to get rid of mutual interference simply by spreading the sensors over a sufficiently large distance.

Answer 2

It depends on which sensors, how they are implemented and how they are interrogated.
If with a digital output, then usually it doesn’t matter - in these modules all the necessary power filtering is implemented, and there is redundancy in the protocols.
An analog with both power and data needs to be well bothered so that there are no interference.
Before isolation, it’s rather unlikely, rather decoupling by RC circuits for power supply and additional stabilization of the reference voltage