With the extreme environment of the process material within the high pressure separator making an accurate level measurement is difficult even though it is highly desirable to do so. With the pressure being higher than most level measurements, it requires proper design. This normally leads to the use of nuclear detectors. The proper design of the system is important in order to get as much information out of the measurement system as possible. Understanding what happens inside the vessel during normal and abnormal operation is critical to design a proper system. This is where the proper care of the detectors also comes into play. You want to be about to safely and reliably measurement system for a relatively long time.