The HI88713 Precision ISO Turbidity Benchtop Meter is specially designed for water quality measurements, providing reliable and accurate readings, even within low turbidity ranges. The instrument is based on a state-of-the-art optical system which guarantees accurate results, assures long term stability, and minimizes stray light and color interferences. Periodic calibration with the supplied standards compensates for any variations in intensity of the tungsten lamp. The 25 mm round cuvettes composed of special optical glass guarantee the repeatability of turbidity measurements. Features at-a-glance: Four Measurement Modes - The HI88713 features four options for turbidity measurement: FNU (Formazin Nephelometric Units), FAU (Formazin Attenuation Units), and NTU (Nephelometric Turbidity Units) ratio and non-ratio mode. Turbidity ranges for each mode are 0.00 to 1000 FNU, 10.0 to 4000 FAU, 0.00 to 4000 NTU (ratio mode), and 0.00 to 1000 NTU (non-ratio mode). Multiple Turbidity Units of Measure - Turbidity can be read as Formazin Nephelometric Units (FNU), Formazin Attenuation Units (FAU), European Brewing Convention units (EBC), and Nephelometric Turbidity Units (NTU). ISO Compliant - The HI88713 meets and exceeds the requirements of ISO 7027 method for turbidity measurements by use of an infrared LED light source. Calibration - The HI88713 has a powerful calibration function that compensates for variation in light intensity.