The Hach Model 2100AN Laboratory Turbidimeter measures turbidity from 0 to 10 000 NTU (Nephelometric Turbidity Units) with automatic range selection and decimal point placement. It can measure solutions with higher turbidity levels by dilution with filtered sample and a simple calculation.


The 2100AN Laboratory Turbidimeter also displays in units of Nephelos (0-67 000 Nephelos), EBCs (European Brewery Convention, 0-2, 450 EBCs), % Transmittance, Absorbence or Colour Units (APHA PTCo Method). In addition, two Application Specific Calibrations may be specified by the analyst. The Application Specific mode uses the Nephelometric optical system in the same manner as the NTU measurement mode. Special method development and sample characterisation also can be accomplished using the signal output from any of the four detectors.

The microprocessor-based Model 2100AN is designed for laboratory use, and employs advanced optical and electronic design. The instrument operates on 230 Vac, and provides a built-in printer, an RS232 output for connection to a printer, data logger or computer, and a recorder output

Principle of Measurement and Specifications

Models 2100AN and 2100N Laboratory Turbidimeters (U.S. Patent 4,198,161) measure in either a ratio or non-ratio mode. Light from the tungsten-filament lamp is focused and passed through the sample. The 90-degree scatter detector receives light scattered by particles. Transmitted and forward scatter detectors receive light that passes through the sample. A back scatter detector in the 2100AN Model measures light scattered back toward the light source.

Ratio and non-ratio measurement modes are selected using the ratio key located on the instrument keyboard. With ratio toggled off, turbidity is measured using only the single 90-degree detector. Benefits of the ratio mode include long-term calibration stability, wide measurement range with excellent linearity, and the ability to measure turbidity in the presence of color.


August 2000 no calibrations have been carried out to date on the instrument.

Date of Purchase

August 1996

Copyright CSIRO 2000
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