ASTM D6855-12 Method for Determination of Turbidity Below 5 NTU in Static Mode

Scope:

 ASTM D6855-12 method compares the intensity of light scattered by the sample with the intensity of light scattered by a reference suspension. ASTM D6855-12 method uses a Nephelometer to trace turbidity in water.

Test Procedure:

ASTM D6855-12 method uses Photoelectric Nephelometer to emit light on a sample containing particulate material, the manner in which the sample interferes with light transmittance is related to the size, shape, and composition of the particles in the water, and also to the wavelength of the incident light. Turbidity Less Than 5.0 NTU—gently inverts the sample several times (1 s inversion cycle) to thoroughly disperse any solids. The sample cell is placed into the instrument at the index to record the reading. Turbidity values are determined by a Nephelometer, which measures light scatter from a sample in a direction that is at 90° concerning the centerline of the incident light path.

Specimen size:

Water sample containing particulate materials

Data:

The instrument measures the range from ≤0.02 to 5.0 NTU.