Reducing process noise in superconducting helium liquid level probes

This memo presents methods to reduce the process noise accompanying the use of superconducting helium liquid level probes in a splashing environment. The development of these methods followed unsatisfactory operation of unmodified, commercially available, level probes used in each of the 24 valve box dewars of Tevatron refrigerators. The dewars function both as reservoirs of refrigeration and as phase separators at the inlet of the cold compressors used in subatmospheric magnet cooling operation.