For the last 17 years, I’ve worked in level and weighing instrumentation as an Application Engineer. During that time, I have occasionally seen situations where a level sensor or a level transducer has been unreliable due to excessive condensation build-up on its face plate.
How do you know if your level transducer or sensor is not performing correctly?
Operators at most sites perform rotational checks often enough to be able to identify when their instrumentation isn’t performing correctly. When it comes to condensation issues, you’re going to be able to spot the problem pretty early on because your level instrument will either lose its level signal or start acting erratically when overwhelmed by too much condensation. The excess condensation will be apparent on the sensor itself. After your transmitter dries, the level device should start working again without issue. However, depending on the environment your instrumentation is located in, you may have dust or some powdery material that, when moistened or wet, cakes onto the transmitter and potentially causes monitoring issues.
Although it is nearly impossible to remove condensation in some environments, we have found some ways to mitigate or even avoid the adverse effects caused by condensation.
- Radiant barrier works by preventing radiation cooling of the sensor to the point where the temperature is below the dew point on a clear night. Radiant barrier is more effective on a clear night than on a cloudy night but can still help to some extent.
- Tilting the transducer slightly one or two degrees does the job in most cases.
- Applying Rain-X on the tilted transducer face will also assist in clearing/condensate build-up from the transducer face.
These ideas are sensor installation dependent and will often require experimentation to determine what works to reliably avoid or significantly reduce condensation and therefore improve the sensor performance. There is a cost benefit factor in order to implement one or more of these ideas that must be weighed by the end user.
Keep in mind the need to resort to the suggestions above would only be in an extreme case of condensation. By design, the pulsating action on the face of the transducers is sufficient to vaporize most condensation that otherwise will form on the sensor. But, if your application results in excessive condensation, the above suggestions are a good approach to consider tackling such nuisances.
What applications do you have issues with due to condensation?