I am interested in using the Temperature Sensor - Waterproof (DS18B20) in a project I’m working on. This project requires temperature readings with prolonged exposure and submersion in seawater. As such, I was curious as to alloy of stainless steel is used for the tube because I don’t want pitting or corrosion to occur. I was also curious as to how much of the sensor is required to be exposed to obtain temperature readings. Is temperature read by conduction through the tube or some other way? Can just the tip be exposed?
Thank you for responding so quickly. I was not aware the tube was covered by a rubber sheathing, as it was not indicated in the specifications, and there are black alloys of stainless steel. But I’m happy to hear that it is.
I understand the probe end is the only thing that produces the temperature readings. My question was how much of the probe has to be exposed to obtain those readings. Is it required for the entire probe to be in contact with the substance it’s measuring the temperature, or could it be enclosed on all sides except the top?
I imagine it’ll probably need to be mostly exposed but can’t say for sure. You’ll likely need to test it to be certain…place it fully in a known temperature bath, record the output…then place just the tip and see if the output is near the same
Since the measuring device is a component inside the stainless tube, I would make the assumption that the entire tube must be acclimated to the temperature of interest. In other words, the tube heats the sensor so you want the tube conditions stable and predicable. Half dipped won’t work well unless the air and liquid temps are very close AND the liquid level is maintained OR you do a bunch of compensation studies and calcs. In any case, the insulating rubber will slow the response and complete immersion will help it along.