1、Designation: D 7315 07aStandard Test Method forDetermination of Turbidity Above 1 Turbidity Unit (TU) inStatic Mode1This standard is issued under the fixed designation D 7315; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the static determination ofturbidity in water. Static refers to a sample that is removed
3、from its source and tested in an isolated instrument. (SeeSection 4.)1.2 This test method is applicable to the measurement ofturbidities greater than 1.0 turbidity unit (TU). The upper endof the measurement range was left undefined because differenttechnologies described in this test method can cove
4、r verydifferent ranges. The round robin study covered the range of04000 turbidity units because instrument verification in thisrange can typically be covered by standards that can beconsistently reproduced.1.3 Many of the turbidity units and instrument designscovered in this test method are numerica
5、lly equivalent incalibration when a common calibration standard is appliedacross those designs listed in Table 1. Measurement of acommon calibration standard of a defined value will alsoproduce equivalent results across these technologies.1.3.1 In this test method calibration standards are oftendefi
6、ned in NTU values, but the other assigned turbidity units,such as those in Table 1 are equivalent. For example,a1NTUformazin standard is alsoa1FNU,a1FAU,a1BU,andsoforth.1.4 This test method does not purport to cover all availabletechnologies for high-level turbidity measurement.1.5 This test method
7、was tested on different natural watersand wastewater, and with standards that will serve as surro-gates to samples. It is the users responsibility to ensure thevalidity of this test method for waters of untested matrices.1.6 Depending on the constituents within a high-levelsample, the proposed sampl
8、e preparation and measurementmethods may or may not be applicable. Those samples with thehighest particle densities typically prove to be the most difficultto measure. In these cases, and alternative measurementmethod such as the process monitoring method can be consid-ered.1.7 This standard does no
9、t purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Refer to the MSDSsfor all chemicals use
10、d in this procedure.2. Referenced Documents2.1 ASTM Standards:2D 1129 Terminology Relating to WaterD 1193 Specification for Reagent WaterD 1889 Test Method for Turbidity of Water3D 2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD 4411 Guide f
11、or Sampling Fluvial Sediment in MotionD 5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD 6855 Test Method for Determination of Turbidity Below5 NTU in Static ModeE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a
12、 Test Method2.2 Other Referenced Standards:USEPA Method 180.1 Methods for Chemical Analysis ofWater and Wastes, Turbidity4ISO 7027 Water QualityDetermination of Turbidity5United States Geological Survey (USGS) National FieldManual for the Collection of Water Quality Data63. Terminology3.1 Definition
13、sFor definitions of terms used in this testmethod refer to Terminology D 1129.3.2 Definitions of Terms Specific to This Standard:1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.07 on Sediments, Geomor-phology, and Open-Ch
14、annel Flow.Current edition approved Aug. 1, 2007. Published August 2007. Originallyapproved in 2007. Last previous edition approved in 2007 as D 7315 07.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSt
15、andards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from United States Environmental Protection Association (EPA),Ariel Rios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http:/www.epa.gov.5Available from International Organiza
16、tion for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.6Available from United Stated Geological Survey (USGS), 12201 Sunrise ValleyDrive, Reston, VA 20192, http:/www.usgs.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700
17、, West Conshohocken, PA 19428-2959, United States.3.2.1 turbidityan expression of the optical properties of asample that causes light rays to be scattered and absorbedrather than transmitted in straight lines through the sample.Turbidity of water is caused by the presence of suspended anddissolved m
18、atter such as clay, silt, finely divided organicmatter, plankton, other microscopic organisms, organic acids,and dyes.3.2.2 turbidimeteran instrument that measures light scat-ter, attenuation, or both in a sample and quantitatively convertsthe light scatter, the attenuation, or both to a displayed v
19、alue.The location and type and number of detectors used will dictatethe relative sensitivity for a typical technology. See Table 1 forexamples of designs.3.2.3 reference turbidity standarda standard that is syn-thesized reproducibly from traceable raw materials by a skilledanalyst. All other standar
20、ds are traced back to this standard.The reference standard for turbidity is formazin (see 9.2.2).3.2.4 calibration turbidity standarda turbidity standardthat is traceable and equivalent to the reference turbiditystandard to within defined accuracy, including commerciallyprepared 4000 NTU Formazin, s
21、tabilized formazin (see 9.2.3),and styrenedivinylbenzene (SDVB) (see 9.2.4). These stan-dards may be used to calibrate the instrument.NOTE 1Calibration standards may be instrument design specific.NOTE 2Calibration standards that exceed 10 000 turbidity units arecommercially available.TABLE 1 Summary
22、 of Known Instrument Designs, Applications, Ranges, and Reporting UnitsDesign andReporting UnitProminent Application Key Design FeaturesTypicalInstrument RangeSuggestedApplication RangesNephelometric non-ratio(NTU)White light turbidimeters. Complywith USEPA Method 180.1 for lowlevel turbidity monito
23、ring.Detector centered at 90 relativeto the incident light beam. Uses awhite light spectral source.0.040 0.040 RegulatoryRatio White Lightturbidimeters (NTRU)Complies with ISWTR regulationsand Standard Method 2130B. Canbe used for both low and highlevel measurement.Used a white light spectralsource.
24、 Primary detector centeredat 90. Other detectors located atother angles. An instrumentalgorithm uses a combination ofdetector readings to generate theturbidity reading.010 000 040 Regulatory010 000 otherNephelometric, near-IRturbidimeters, non-ratiometric(FNU)Complies with ISO 7027. Thewavelength is
25、 less susceptible tocolor interferences. Applicable forsamples with color and good forlow level monitoring.Detector centered at 90 relativeto the incident light beam. Uses anear-IR (780900 nm)monochromatic light source.01000 040 Regulatory (non-US)01000 otherNephelometric near-IRturbidimeters, ratio
26、 metric(FNRU)Complies with ISO 7027.Applicable for samples with highlevels of color and for monitoringto high turbidity levels.Uses a near-IR monochromaticlight source (780900 nm).Primary detector centered at 90.Other detectors located at otherangles. An instrument algorithmuses a combination of det
27、ectorreadings to generate the turbidityreading.010 000 040 Regulatory010 000 otherSurface Scatter Turbidimeters(NTU)Turbidity is determined throughlight scatter from or near thesurface of a sample.Detector centered at 90 relativeto the incident light beam. Uses awhite light spectral source.1010 000
28、1010 000Formazin Back Scatter (FBU) Not applicable for regulatorypurposes. Best applied to highturbidity samples. Backscatter iscommon with but not all onlyprobe technology and is bestapplied in higher turbiditysamples.Uses a near-IR monochromaticlight source in the 780900 nmrange. Detector geometry
29、 is or ) critical value from table. The resultwill determine if the duplicate values are acceptable.15.4.3 If the result exceeds the precision limit as derivedfrom the F test, the batch must be reanalyzed or the resultsmust be qualified with an indication that they do not fall withinthe performance
30、criteria of the test procedure.15.5 Independent Reference Material (IRM):15.5.1 In order to verify the quantitative value produced bythe test procedure, analyze an IRM submitted as a regularsample to the laboratory at least once per quarter. The value ofthe IRM should be in the range of the determin
31、ations that thelab normally determines during the analyses of samples. Thevalue obtained must fall within the control limits specified bythe provider of the IRM.16. Precision and Bias816.1 This test method was tested on 21 different laboratoriesthat were assembled at a common site. Each laboratoryco
32、nsisted of an operator and an instrument (turbidimeter) thatoperated using a specific technology and traceable reportingunit that was listed in Table 1. Testing was conducted over atwo-day period. Fig. 6 is a breakdown of the different labora-tories.16.1.1 Samples24 samples were analyzed in this rou
33、ndrobin. These were broken down into surrogates, real worldenvironmental samples, and United States Geological SurveyQuality Control Samples (USGS QC).16.1.1.1 Surrogate samples were samples of a defined tur-bidity value and prepared from turbidity standard materials.Specifically, these were formazi
34、n, stabilized formazin, andstyrene divinylbenzene (SDVB) materials. Surrogate sampleswere prepared at defined values, but were run as unknownsduring the round robin study. A total of six surrogate sampleswere run.16.1.1.2 Real world environmental samples were samplesthat were collected in the field
35、and shipped to the round robintest site. No preservation action was taken with these samples.Samples were prepared immediately before and during dispen-sation to each of the laboratories. Real world samples includedsamples from streams and ponds. A total of 13 real worldenvironmental samples were an
36、alyzed.16.1.1.3 USGS QC samples were samples that were pre-pared by the USGS branch of quality systems immediatelyprior to analysis. These samples had defined quantities of sandsand fines.Atotal of five different samples were run through thisround robin.16.2 Sample Preparation and MeasurementEach bu
37、lksample was mixed using a churn splitter, which is designed tomaintain particulate suspensions and homogeneity throughoutthe bulk sample. Samples were dispensed to each laboratory atthe same time and were mixed throughout the dispensationprocess. Once the samples were dispensed, they were preparedf
38、or measurement as prescribed in Section 13 of this testmethod. A total of three measurements were made of each8Supporting data for the precision and bias statements have been filed at ASTMHeadquarters. Request RR: D19-1179.TABLE 7 ASTM E 691 Data Analysis: Comparison Across Laboratories Reporting wi
39、th Broad-Band Light Sources from 400700 nmReporting: ASTM High Level Turbidity Measurement in the Static ModeRound Robin StudyOctober 2005Finalized for All EPA (400600 nm Light Source) Labs Analysis: NTU, NTRU, and AUMaterialAllLaboratoriesAverageTUWithinLaboratoryRepeatabilityTUBetweenLaboratoriesR
40、eproducibilityTUSingle OperatorSo*RepeatabilityTUExpectedTUOverallBiasTUTestSequenceNumber ofLabs ReportingSurrogates SDVB #2 2 NTU 2.5839 0.0476 0.4532 0.0170 2.000 0.5839 6 6Formazin A 81.4867 1.1680 6.7434 0.4171 83.800 2.3133 1 5StablCal B 286 283.6667 1.4459 29.1836 0.5164 286.000 2.3333 4 5For
41、mazin B 496.0000 12.0324 48.1558 4.2973 507.100 11.1000 2 5SDVB #2 800 NTU 487.2500 1.1431 630.2388 0.4082 800.000 312.7500 7 4Formazin C 1423.3333 6.1910 49.6191 2.2111 1433.000 9.6667 3 3RealWorldSamplesAcid Mine 1 80.6867 3.4551 53.4877 1.2340 8 5Acid Mine Dup 77.6667 5.8049 54.7076 2.0732 9 5Alk
42、 Glac Flr 100% 1896.6667 105.6111 994.6820 37.7183 10 2Alk Glac Flr 100% Dup 1165.6667 842.0044 980.2578 300.7158 11 2Alk Glac Flr 50% 776.2222 24.8519 279.7650 8.8757 12 3Alk Glac Flr 25% 342.5333 50.5295 255.9977 18.0462 13 5Kansas 100% 1814.8333 28.8731 694.7446 10.3118 14 2Kansas 100% Dup 1823.1
43、667 46.7413 679.8899 16.6933 15 2Kansas 50% 890.8889 31.5820 473.9575 11.2793 16 3Kansas 50% Dup 890.8889 27.5294 450.2106 9.8319 17 3Kansas 25% 397.2667 25.3345 356.9925 9.0480 18 5Kansas 4.2% 53.6611 3.9061 53.8016 1.3950 19 6Reston Pond No Filt 28.0000 3.7234 16.0483 1.3298 20 6USGSQCUSGS QC #1 1
44、0.3506 2.1348 7.3748 0.7624 21 6USGS QC #2 30.1867 4.5935 23.9715 1.6405 22 5USGS QC #3 138.2333 17.1807 97.4127 6.1360 23 5USGS QC #4 126.0000 16.2946 74.8351 5.8195 24 5USGS QC #5 318.6667 14.2955 270.3274 5.1056 25 5D 7315 07a14sample. A measurement included a new dispensation, prepara-tion, and
45、measurement in the respective measurement. Thesetriplicate measurements were then recorded and used in thePractice E 691 data analysis methods.16.3 ResultsResults from this study were expressed inTables 3-7. One of the objectives of this round robin was todemonstrate that different technologies can
46、deliver differentresults on the same sample. Thus, results have been grouped toshow several different comparisons among technologies.Within each table, a generic unit of “TU” is displayed, whichis to infer that depending on the technology used, a specificreporting unit would be displayed.16.3.1 All
47、LaboratoriesTable 3 shows the Practice E 691comparison across all laboratories. Laboratories include: ratioand non-ratio technologies, different light sources (white light,IR, defined wavelengths), and different detection angles (at-tenuated, nephelometric, backscatter). For certain samples, theturb
48、idity value may have been outside the measurement rangefor that specific laboratory. For example, some laboratories areonly capable of measuring samples at or below 40 turbidityunits and for these laboratories, any sample that has a valueabove 40 turbidity units will be above the measurement rangeof
49、 the respective technology for that laboratory (that is, theinstrument). Thus, depending on the sample, the number of thelaboratories participating will vary. The same condition is alsotrue for Tables 4-7.16.3.2 The analysis of data that was generated by ratiotechnologies is represented in Table 4. A ratio laboratory has anephelometric detector plus one or more detectors at otherangles. All detectors work together to determine the turbidityvalue of the sample. The reporting units represented in thistable are NTRU, and FNRU.16.3.3 Table
