ASTM D7315-12
Standard Test Method for Determination of Turbidity Above 1 Turbidity Unit (TU) in Static Mode
- Standard No.
- ASTM D7315-12
- Release Date
- 2012
- Published By
- American Society for Testing and Materials (ASTM)
- Status
- Replace By
- ASTM D7315-17
- Latest
- ASTM D7315-17(2023)
- Scope
Turbidity at the levels defined in the scope of this test method are often monitored to help control processes, monitor the health and biology of water environments and determine the impact of changes in response to environmental events (weather events, floods, etc.). Turbidity is often undesirable in drinking water, plant effluent waters, water for food and beverage processing, and for a large number of other water-dependent manufacturing processes. Removal is often accomplished by coagulation, sedimentation, and various levels of filtration. Measurement of turbidity provides an indicator of contamination, and is a vital measurement for monitoring the characteristics and or quality within the sample’s source or process.
This test method does overlap Test Method D6855 for the range of 1–5 TU. If the predominant measurement falls below 1.0 TU with occasional spikes above this value, Test Method D6855 may be more applicable. For measurements that are consistently above 1 TU, this test method is applicable.
This test method is suitable to turbidity such as that found in all waters that measure above 1 NTU. Examples include environmental waters (streams, rivers, lakes, reservoirs, estuaries), processes associated with water pollution control plants (wastewater treatment plants), and various industrial processes involving water with noticeable turbidity. For measurement of cleaner waters, refer to Test Method D6855.
The appropriate measurement range for a specific technology or instrument type that should be utilized is at or below 80 % of full-scale capability for the respective instrument or technology. Measurements above this level may not be dependable.
Dilutions of waters are not recommended, especially in the case of samples with rapidly settling particles (that is, sediments). It is recommended that an appropriate instrument design that covers the expected range be selected to avoid the need to perform dilutions.
Technologies described in this standard may not measure all aspects (absorption and scatter) of a sample. Some of the properties of the water, the suspended material, or both may interfere with the certain measured property of the sample, such as the scattering of light that the particular instrument is measuring.
Several different technologies are available for use in the measurement of high-level turbidity. Some technologies may be better suited for specific types of samples, depending on the application and measurement criteria. Please refer to Table 1 and Appendix X1 which is a flow chart to help assist in selecting the best technology for the specific application.
When measuring high levels of turbidity the samples will often contain significant interferences such as that from absorbing particles, absorbance in the matrix, and rapidly settling particles. These may have a significant impact on how one measurement technology responds to changes in turbidity. Often times it will be prudent to run a series of linear dilutions to determine if the measured response was expected relative to the dilution. In cases where the response to dilution ratio is linear, the technology may be adequately accounting for the interferences. If the response is not expected, another technology should be considered to determine if a more accurate measurement could be obtained.
When reporting the measured result, appropriate units should also be attached. The units are reflective of the technology used to generate the measurements. The intention is to provide traceability for the technology used to generate the measured result, and if ........
ASTM D7315-12 Referenced Document
- ASTM D1129 Standard Terminology Relating to Water
- ASTM D1193 Standard Specification for Reagent Water
- ASTM D1889 Standard Test Method for Turbidity of Water
- ASTM D2777 Standard Practice for Determination of Precision and Bias of Applicable Methods of Committee D-19 on Water
- ASTM D4411 Standard Guide for Sampling Fluvial Sediment in Motion
- ASTM D5847 Standard Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
- ASTM D6855 Standard Test Method for Determination of Turbidity Below 5 NTU in Static Mode
- ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
- ISO 7027 Water quality - Determination of turbidity
ASTM D7315-12 history
- 2023 ASTM D7315-17(2023) Standard Test Method for Determination of Turbidity Above 1 Turbidity Unit (TU) in Static Mode
- 2017 ASTM D7315-17 Standard Test Method for Determination of Turbidity Above 1 Turbidity Unit (TU) in Static Mode
- 2012 ASTM D7315-12 Standard Test Method for Determination of Turbidity Above 1 Turbidity Unit (TU) in Static Mode
- 2007 ASTM D7315-07a Standard Test Method for Determination of Turbidity Above 1 Turbidity Unit (TU) in Static Mode
- 2007 ASTM D7315-07 Standard Test Method for Determination of Turbidity Above 1 Turbidity Unit (TU) in Static Mode
