Artcile on IR distance measurement

[Ioannis]

Unless the sensor is well isolated with a special cable too, this is also a good option (Classic 4-20mA too).

But in general is in my opinion, better not to immerse anything electronics in the water. Keep them out, in an controlled place.

Ioannis

[mackrackit]

Unless the sensor is well isolated with a special cable too, this is also a good option (Classic 4-20mA too).

But in general is in my opinion, better not to immerse anything electronics in the water. Keep them out, in an controlled place.

Ioannis

That is where snubbers come in handy to isolate the sensor. But a good stainless steel sensor should work with water just fine. I have used this type of thing with products ranging from a pH of 1 to 13.

Many options. What are the tank dimensions?

[El_AMPo]

Just to add a drop ,

I've built a proximity sensor from IR led + IR-VIs Phototransistor for the pic.

Really a low parts count solution and works like charm in the range of 2-30cm if you apply 2 or 3 layers of filtering.

Anyway, stay away from light reflection methods if you need an accurate linear response according to distance, or be prepared for resolution problems and lookup tables