The ProGap S microwave barrier is a universal sensor with a flexible range of applications, consisting of a transmitter and receiver on the basis of the latest microwave technology. It is used to detect the limit level of dry bulk solids of all types or to position objects. The microwave barrier is a contactless measuring procedure. It can be installed in containers, pipelines, shafts or free-fall sections. The range, depending on the model, is either 0 … 4 m or 0 … 18 m. Larger ranges can also be realised. If container walls, housings or pipelines are not metal, it is possible to measure from the outside. This even makes it possible to completely uncouple the measurement from the process through suitable windows (made of non-metallic materials). This is especially interesting in the use of aggressive, abrasive or coarse materials or in cases of extreme pressures and temperatures. With the help of a process adapter, the ProGap S can also be used under difficult conditions such as in dust ex-zones. The use of microwaves also ensures a high level of insensitivity to any caking on the sensor window.