Looking for suggestions on measuring the temperature of a body of water that may rise and fall 10-15 feet. I need to send a 4-20Ma signal to a DCS or PLC. I considered a Rosemount tranmitter with remote RTD sensor but am not sure how I would mount this probe and thermowell deep enough to always be submerged. Has anybody done this before or have any suggestions???

 

We did something like this with RTDs on small bouys in a river. With an RF modem, everything worked great.

 

Think of a buoy.

 

You would need to define what temperature. Still water stratifies so temperature will depend on depth. For consistancy, a sensor suspended by a float is often used. It would seem a good way to solve your level variation as well.

Regards

cww

 

Hi... I would still try Rosemount and inquire about one their averaging RTD's model#1082 averaging sensors. They are available in a variety of configurations of points and lengths. You could also RF this signal bal to your PLC or DCS within limits... otherwise you will need a data logger of some sort and then manually retreive the data.

Cheers!!!