TURBIDITY METER Milwaukee Mi415 has two operating ranges; 0.00 to 50.00 FNU, and 50to 1000 FNU that can accommodate the most turbid condition you may encounter. Turbidity refers to the concentration of undissolved, suspended particles present in a liquid. Turbidity is a measure of the clarity of a sample. For potable water applications turbidity is a good indicator of water quality. Turbidity Measurement is achieved by analyzing the amount of light refracted from suspended particles such as clay, silt and organic material. By measuring turbidity, by photometric or tube methods, it is possible to estimate suspended solids content. Turbidity Range     0.00 - 50.00 FNU; 50 - 1000 FNU Resolution     0.01 FNU; 1 FNU Accuracy     ± 0.5 FNU or ± 5% of reading,  whichever is greater Method     Detection of scattered light Light Detection     High emission infrared LED Calibration     Automatic Auto-Off     After 5 minutes of non-use Battery Type     9v Transistor - Included