Thermography is a powerful tool for locating or verifying levels
in tanks and silos. But one could ask “Why bother?” All too often
existing level indication instruments are simply not reliable or
positive verification of instrumentation readings is required.
When properly used, thermography can reveal not only the
liquid/gas interface, but also sludge buildup and floating
materials such as waxes and foams. Similar techniques can be
used to locate levels and bridging problems in silos containing
This paper discusses the parameters and limitations that must be
addressed, shows techniques that can be employed, and illustrates
the discussions with numerous thermal images.