Is there any difference how the probe is operating when selecting between the turbidity units FNU, NTU, and EBC?
TSS portable correlation between FNU, NTU, and EBC
FNU and NTU are equal and are just a different name for the unit of turbidity. EBC is the unit for turbidity defined by the European Brewery Convention. It is meant to be used by breweries: 1 FNU = 0.25ECB