Radiometric measurements for industrial processes have been around for several decades. They are an important component in the performance of critical level, density and flow measurements. Nuclear measurement gauges work where conventional measuring technology fails. They offer outstanding measurement results under extreme conditions. High temperatures, pressures and other difficult ambient and process conditions are no problem for radiometric measurements. Typical measurement tasks are non-contact level and density measurements in various vessels, bunkers and piping systems, interface measurements in oil separators and moisture measurement. They can also be used as non-contact limit switches.