There are important considerations when choosing an LFL monitor: Response Accuracy, Response Speed, Condensation Issues and Failsafe. We've discussed response accuracy and response speed, let's look at condensation issues:
To ensure that the vapor concentration reaching the analyzer is exactly the same as the concentration at the point of origin, the sample must always be kept in a vapor state. The analyzer, the sample line and any other elements of the sample train may have to be heated to keep the sample above its dew point.
If allowed to cool, the sample may condense, causing process components to drop-out, which will compromise reading accuracy and potentially result in clogging of the sample train, requiring maintenance and causing downtime.
When determining the operating temperature required for the analyzer and sample line, it is important to calculate the flash points or condensation temperatures of all substances in the sample atmosphere, even those that are not flammable. Any substance can clog the sample line or analyzer if it is allowed to condense.