ASTM D5543-2015 Standard Test Method for Low-Level Dissolved Oxygen in Water《水中低水平溶解氧的标准试验方法》.pdf

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1、Designation: D5543 09D5543 15Standard Test Method forLow-Level Dissolved Oxygen in Water1This standard is issued under the fixed designation D5543; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number

2、 in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of low-level (100 g/L) dissolved oxygen in thermal-cycle steam condensate,deaerated boiler feedwate

3、r, boiler water, and deaerated deionized water. The following test method is included:Range, g/L SectionsColor Comparator TestMethod Using Self-Filling GlassAmpoules0 to 100 8 to 171.2 This test method may be applicable to electronic-grade, pharmaceutical-grade, and other high-purity waters, althoug

4、h thesewere not addressed in the collaborative study.1.3 This test method is a colorimetric procedure applicable to dissolved oxygen in water in the range from 0 to 100 g/L.1.4 It is the users responsibility to ensure the validity of these test methods for waters of untested matrices.1.5 The values

5、stated in SI units are to be regarded as the standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability o

6、f regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1066 Practice for Sampling SteamD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterD3370 Pr

7、actices for Sampling Water from Closed Conduits3. Terminology3.1 Definitions: For definitions of terms used in these test methods, refer to Terminology D1129.4. Significance and Use4.1 Dissolved oxygen is detrimental in certain boiler and steam cycles because it may accelerate corrosion. Concentrati

8、onsabove 10 g/L are unacceptable in many high-pressure boiler systems. The efficiency of dissolved oxygen removal from boilerfeedwater by chemical or mechanical means, or both, is determined by measuring the concentration before and after the process.The measurement is also made to check for air lea

9、kage into the boiler system.4.2 The oxygen treatment method for boiler corrosion reduction requires injection of oxygen into the boiler feedwater. Theresulting oxygen level is monitored for control purposes.5. Reagents5.1 This test method does not require the preparation of any reagents. All the nec

10、essary analytical reagents are provided by themanufacturer in sealed ampoules.1 These test methods are under the jurisdiction of ASTM Committee D19 on Water and are the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits, Analysis of Water for Power Generation and

11、 Process Use, On-Line Water Analysis, and Surveillance of Water.Current edition approved Oct. 1, 2009Feb. 1, 2015. Published October 2009May 2015. Originally approved in 1994. Last previous edition approved in 20052009 asD5543 94D5543 09. (2005). DOI: 10.1520/D5543-09.10.1520/D5543-15.2 For referenc

12、edASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the u

13、ser of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard

14、as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2 Purity of WaterReference to water shall mean water that meets or exceeds the quantitative specifications for Type IIrea

15、gent water of Specification D1193, Section 1.1.6. Precautions6.1 Users must exercise caution by using finger cots, in accordance with the manufacturers instructions, when handling themixing of sample and reagent in the glass ampoules.7. Sampling7.1 Sampling is the most critical part of any dissolved

16、 oxygen test. The sample stream must be completely leak-free, since eventhe smallest leak can elevate the oxygen level in the sample and cause large errors in the results. New or intermittently usedsampling systems must be purged for a minimum of 4 h. Sample streams that are used routinely may requi

17、re only a few minutesof purging.7.2 Collect the samples in accordance with Practices D1066 and D3370.7.3 With water under pressure, connect a tube of inert material to the inlet and extend the tube outlet to the bottom of the samplebottle or tube. Use stainless steel, Type 304 or 316, or glass tubin

18、g with short neoprene connections. Do not use copper tubing,long sections of neoprene tubing, or other types of elastomeric polymeric materials. If the water being sampled is above roomtemperature, the sample line shall contain a suitable cooling coil to cool it to approximate room temperature.COLOR

19、 COMPARATOR TEST METHOD USING SELF-FILLING GLASS AMPOULES1. Scope1.1 This test method covers the rapid, routine rapid determination of low-level (100 g/L) dissolved oxygen in thermal-cyclesteam condensate, deaerated boiler feedwater, boiler water, and deaerated deionized water. Color comparators all

20、ow the estimationof concentrations ranging from 0 to 100 g/L (ppb) oxygen.1.2 This test method may be applicable to electronic-grade, pharmaceutical-grade, and other high-purity waters, although thesewere not addressed in the collaborative study.1.3 This test method was tested in steam condensate, d

21、eaerated boiler feedwater, and deaerated deionized water. It is the usersresponsibility to ensure the validity of thethis test method for waters of untested matrices.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This

22、 standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.

23、1 ASTM Standards:2D1066 Practice for Sampling SteamD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD5463 Guide for

24、 Use of Test Kits to Measure Inorganic Constituents in Water3. Terminology3.1 DefinitionsFor definitions of terms used in this test method, refer to Terminology D1129.4. Summary of Test Method4.1 The tip of a partially evacuated sealed ampoule is broken while submerged in a flowing water sample. The

25、 sample is drawninto the ampoule where it reacts instantaneously with the oxygen-sensitive indicator (leuco form of Rhodazine D) to produce areddish violet color whose intensity is proportional to the concentration of dissolved oxygen.35. Significance and Use5.1 Dissolved oxygen is detrimental in ce

26、rtain boiler and steam cycles because it may accelerate corrosion. Concentrationsabove 10 g/L are unacceptable in many high-pressure boiler systems. The efficiency of dissolved oxygen removal from boiler3 Spokes, G. N., Dissolved Oxygen in Water Measurement and Standardization, EPRI PWR Plant Chemis

27、ts Meeting, San Diego, CA, Nov. 1720, 1992. Copies obtainablefrom CHEMetrics Inc., Route 28, Calverton, VA 20138.Spokes, G. N., Dissolved Oxygen in Water Measurement and Standardization, EPRI PWR Plant Chemists Meeting,San Diego, CA, Nov. 1720, 1992. Copies obtainable from CHEMetrics Inc., 4295 Catl

28、ett Rd., Midland, VA 22728, https:/.D5543 152feedwater by chemical or mechanical means, or both, is determined by measuring the concentration before and after the process.The measurement is also made to check for air leakage into the boiler system.5.2 The oxygen treatment method for boiler corrosion

29、 reduction requires injection of oxygen into the boiler feedwater. Theresulting oxygen level is monitored for control purposes.6. Interferences6.1 Color, turbidity, and oxidizing impurities interfere in this test method to yield high results. If the sample is colored or turbidor contains oxidizing i

30、mpurities, the amount of interference that may be contributed by such effects must be determinedindependently prior to using this test method.6.2 Easily reduced metal ions may interfere in this test method to cause high results. For example, 100 g/L (ppb) Cu+2 mayappear as 5 g/L (ppb) dissolved oxyg

31、en, and 100 g/L Fe+3 may appear as 7 g/L dissolved oxygen. However, less than 50 g/LCu+2 or Fe+3 cause less than 1-g/L interference.6.3 Hydrogen peroxide alone in concentrations up to 200 g/Ldoes not affect the measurement of 1.4 g/Lof dissolved oxygen.Above 200 g/L hydrogen peroxide, there is a pos

32、itive interference of 3.3 g/L dissolved oxygen per 100 g/L excess over 200g/L hydrogen peroxide.6.4 The following interferences occur in the presence of 2200 mg/L boron present as boric acid: (1) at pH levels below pH 6,recovery can be as low as 80 %; (2) added hydrogen peroxide at a concentration o

33、f 0.1 mg/L yields a positive interference of 10g/L dissolved oxygen; and (3) added hydrogen peroxide in a concentration range from 0.5 to 650 mg/L yields a positiveinterference of 20 to 25 g/L.NOTE 1Measurements of 0 to 100 g/L of dissolved oxygen are unaffected by the presence of 2200 mg/L boron pr

34、esent as boric acid at pH 6 andabove in the absence of hydrogen peroxide.6.5 Benzoquinone, an oxidation product of hydroquinone, interferes with this test method. One hundred micrograms per litreof benzoquinone may appear as 33 g/L dissolved oxygen.6.6 Reducing agents such as hydrazine and sulfite d

35、o not interfere at 5-mg/L (ppm) levels in the sample.6.7 Ampoules must be protected from light to prevent darkening. Follow the manufacturers storage recommendations.6.8 Color comparator tubes must be protected from light to prevent fading. Follow the manufacturers storage recommenda-tions.7. Appara

36、tus7.1 Color Comparator, for 0, 2, 4, 6, 8, 12, 16, and 20 g/L (ppb) of oxygen.7.2 Color Comparator, for 0, 5, 10, 15, 20, 25, 30, and 40 g/L (ppb) of oxygen.7.3 Color Comparator, for 0, 10, 20, 30, 40, 60, 80, and 100 g/L (ppb) of oxygen.7.4 Sampling Tube. See Fig. 1.8. Reagents and Materials8.1 Se

37、aled, evacuated glass ampoules containing oxygen-sensitive indicator.This test method does not require the preparationof any reagents. All the necessary analytical reagents are provided by the manufacturer in sealed ampoules.8.2 Purity of WaterReference to water shall mean water that meets or exceed

38、s the quantitative specifications for Type IIreagent water of Specification D1193, Section 1.1.9. Precautions9.1 Users should review the manufacturers kit instructions before use.10. Sampling10.1 Sampling is the most critical part of any dissolved oxygen test.The sample stream must be completely lea

39、k-free, since eventhe smallest leak can elevate the oxygen level in the sample and cause large errors in the results. New or intermittently usedsampling systems must be purged for a minimum of 4 h. Sample streams that are used routinely may require only a few minutesof purging.10.2 Collect the sampl

40、es in accordance with Practices D1066 and D3370.10.3 With water under pressure, connect a tube of inert material to the inlet and extend the tube outlet to the bottom of thesample bottle or tube. Use stainless steel, Type 304 or 316, or glass tubing with short neoprene connections. Do not use copper

41、tubing, long sections of neoprene tubing, or other types of elastomeric polymeric materials. If the water being sampled is aboveroom temperature, the sample line shall contain a suitable cooling coil to cool it to approximate room temperature.D5543 15310.4 Attach the feedwater source to the plastic

42、sampling tube as described in 7.310.3. Clamps may be attached to the tube tohold it vertical, or it can be attached to a vertical rod or pipe above a sink, drain, or bucket.11. Calibration and Standardization11.1 No calibration is required.NOTE 2The color comparator standards are precalibrated by th

43、e manufacturer for measurement of dissolved oxygen in water.11.2 A dissolved-oxygen-in-water standard may be generated by following the procedures given in Appendix X1.12. Procedure12.1 Insert the ampoule into the sampling device, with the pointed end down.Allow the sample to flow at least 5 min.A15

44、-minwait time may be necessary to achieve the best accuracy for samples with below 20 g/L of dissolved oxygen.12.2 Gently press the ampoule toward the wall of the sampling tube to snap off the tip, and remove the ampoule, keeping thetip down, immediately after filling is complete.12.3 Using a protec

45、tive rubber finger cot, place a finger over the broken tip. (WarningGlass may be sharp.Warning)glassmay be sharp.) Invert the ampoule several times to mix the contents, allowing the bubble to travel from end to end each time. Wipeall liquid from the exterior of the ampoule.NOTE 3A small bubble of in

46、ert gas will remain in the ampoule to facilitate mixing.NOTE 4Due to the possibility of air leaking in during this step, it is advisable to run tests in duplicate. It should be noted, however, that some variationin observed concentrations may be due to changes in system conditions.12.4 Use the color

47、 comparator as illustrated in Fig. 2 to determine the level of dissolved oxygen in the sample. Place theampoule in the center (empty) tube of the comparator, with the flat end downward. Direct the top of the comparator toward a sourceof bright, white light while viewing from the bottom. Hold the com

48、parator in a nearly horizontal position, and rotate it until thecolor standard below the ampoule shows the closest match. Complete this color matching procedure in less than 30 s after snappingthe tip in the sample.NOTE 5The color intensity may continue to increase after the rapid initial color reac

49、tion. However, it is the initial color reaction that is completewithin 30 s, and to which the system calibrations apply.12.4.1 Find the analytical result from the concentration value of the closest matching color standard as designated on thecomparator label. Estimate the concentration to within a half color standard interval.13. Calculation13.1 The dissolved oxygen content of the sample is the value obtained in 15.412.4.1. Use the average of the two resulting valuesif two ampoules are used.FIG. 1 Sampling Tube