Water I.D. Primelab 2.0, Manual

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The turbidity test measures the optical value of the sample which results from the scattering and
absorption of light particles. The amount of turbidity depends on variables such as size, shape,
colour and the refractive nature of the particles.This test is calibrated using Formazin Turbidity
Standards and the readings are in terms of FAU (Formazin Attenuation Units). This test can be
used for daily plant monitoring and 1 FAU is equivalent to 1 NTU (Nephelometric Turbidity Unit).
This test is not suitable for USEPA reporting purposes as the optical method of measurement
for FAU is very different than the NTU method.However 1 NTU = 1 FTU = 1 FAU when traced to
formazin primary standards.
T195/204 T195/204