I have an Endress Hauser FMR20 Radar level Transmitter installed in a cooling tower with the RIAI15 remote level display indicator where when the cooling tower is off we get perfect level readings. But when the cooling tower is running periodically the reading will go stale or stuck at a value for a period anywhere from 5 mins to 2 hours. Then it would start reading correctly and we'd find that the cooling tower overflowed. We've verified all settings on the device, echo mapping ( not sure if this needed to be performed while the tower was running). Installation has been ruled out. Water intrusion has also been ruled out even though sitting in a cooling tower it is constantly getting rained on when the tower is running. We're almost at the decision that maybe this transmitter isn't the correct one for this application.

 

your process operating environment dictates your options, as you have noted.

 

Mapping has to be performed ideally with empty tank, but anyway at a distance that doesn't cover the real echo -> some 10...20 cm higher. Then, if water splashes directly on the radar's antenna it's not good for the level reading. Before moving to a more robust radar or another technology you can try to purchase an accessory available: flooding protection cone. This, screwed on the antenna, creates a kind of stilling chamber protecting from flooding and water splashes

 

Have you considered electrical interference? Do you have power or data cables for this sensor running anywhere near power for fans?

 

I have an Endress Hauser FMR20 Radar level Transmitter installed in a cooling tower with the RIAI15 remote level display indicator where when the cooling tower is off we get perfect level readings. But when the cooling tower is running periodically the reading will go stale or stuck at a value for a period anywhere from 5 mins to 2 hours. Then it would start reading correctly and we'd find that the cooling tower overflowed. We've verified all settings on the device, echo mapping ( not sure if this needed to be performed while the tower was running). Installation has been ruled out. Water intrusion has also been ruled out even though sitting in a cooling tower it is constantly getting rained on when the tower is running. We're almost at the decision that maybe this transmitter isn't the correct one for this application.

Try Guided Wave Radar with a remote mount transmitter it will solve the problem completely. With foam and steam 26ghz needs to be mapped well but is still not a great choice for cooling towers.