BS ISO 11657:2014

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Measuring principles
5 Properties of sediment of importance for
  sediment surrogate techniques
6 Methods for determination of suspended sediment
  concentration by surrogate techniques
7 Calibration and validation
Annex A (informative) - Determination of the
        concentration of suspended sediment by
        optical techniques
Annex B (informative) - Determination of the
        concentration of suspended sediment by
        laser diffraction technique
Annex C (informative) - Determination of the
        concentration of suspended sediment
        by acoustic back scatter
Bibliography

Defines methods for determination of the concentrations and particle-size distributions of suspended sediment in streams and canals by surrogate techniques.

This International Standard specifies methods for determination of the concentrations and particle-size distributions of suspended sediment in streams and canals by surrogate techniques. Methods based on bulk-optical principle of water such as transmission and nephelometry are the most commonly used surrogates for determining suspended sediment concentrations (SSC). Instruments and techniques based on acoustic attenuation and/or acoustic backscatter principles are also in use for measurement of suspended sediment concentration. Instrumentation based on the laser diffraction principle is also used for the measurement of particle size distribution. This International Standard covers brief description of the operating principle of each method and details of some of the instruments available.

The detailed method and principle of optical and acoustical transmission, nephelometry, and optical back scatter (OBS), laser diffraction technique (LD) and acoustic back scatter technique (ABS) with their limitations are described in AnnexA, AnnexB and AnnexC respectively.