Tintometer Inc.: Lovibond TB 6000: Turbidity measurement in a captured sample of drinking water by 660-nm LED
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Official Method Name
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Measurement of Drinking Water Turbidity of a Captured Sample Using the Lovibond Portable Laser Turbidity Method |
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Current Revision
| Revision 1.0, May 5, 2021 |
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Media
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WATER |
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Instrumentation
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Nephelometer |
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Method Subcategory
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Physical |
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Method Source
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Citation
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Brief Method Summary
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The method is based upon a comparison of the intensity of light that is generated by a laser that is scattered by the sample under defined conditions with the intensity of the same laser light scattered by a standard reference suspension. The higher the intensity of scattered light, the higher the turbidity. Readings, in NTU, are made in a nephelometer. |
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Scope and Application
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Turbidity measurement in any colorless drinking water samples with a turbidity less than 10 Nephelometric Turbidity Units (NTU). |
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Applicable Concentration Range
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0 to 10 NTU |
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Interferences
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(A) Floating debris and coarse particulate matter within the sample may settle out of suspension resulting in low turbidity readings. (B) Finely divided air bubbles will cause random high spikes in readings. Incorporate a sample deaerator for the removal of entrained air from the sample stream. (C) Dissolved, light absorbing substances or chemicals in the sample, i.e., the presence of color, can absorb portions of the incident light spectra, resulting in low turbidity readings, although this effect is generally not significant for drinking water. (D) Light-absorbing particles in suspension within the sample, such as activated carbon of significant concentration, can cause low readings. (E) Construction materials of the nephelometric device within the measurement chamber can result in elevated stray light due to spurious reflections of the incident beam can cause a false positive bias at the bottom end of the range. |
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Quality Control Requirements
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CALIBRATION BLANK (CB), INSTRUMENT PERFORMANCE CHECK SOLUTION (IPC), LABORATORY REAGENT BLANK (LRB), PRIMARY CALIBRATION STANDARD (PCAL), QUALITY CONTROL SAMPLE (QCS), SECONDARY CALIBRATION STANDARDS (SCAL), STOCK STANDARD SUSPENSION (SSS), SAMPLE BLANK, Reagent water, turbidity-free |
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Sample Handling
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N/A |
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Maximum Holding Time
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N/A |
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Relative Cost
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Sample Preparation Methods
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