1、Designation:D554315Standard 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 in parenthese
2、s 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 rapid determination oflow-level(100 g/L)dissolved oxygen in thermal-cyclesteam condensate,deaerated boiler feedwater,boiler water,a
3、nddeaerated deionized water.Color comparators allow the esti-mation of 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,althoughthese were not addressed in the collaborative study.1.3 It i
4、s the users responsibility to ensure the validity of thistest method for waters of untested matrices.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns,if a
5、ny,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.2.Referenced Documents2.1 ASTM Standards:2D1066 Practice for Sampling SteamD1129 Terminology R
6、elating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD5463 Guide for Use of Test Kits to Measure InorganicConstituents in Water3.Terminolog
7、y3.1 DefinitionsFor definitions of terms used in this testmethod,refer to Terminology D1129.4.Summary of Test Method4.1 The tip of a partially evacuated sealed ampoule isbroken while submerged in a flowing water sample.Thesample is drawn into the ampoule where it reacts instanta-neously with the oxy
8、gen-sensitive indicator(leuco form ofRhodazine D)to produce a reddish violet color whose intensityis proportional to the concentration of dissolved oxygen.35.Significance and Use5.1 Dissolved oxygen is detrimental in certain boiler andsteam cycles because it may accelerate corrosion.Concentra-tions
9、above 10 g/L are unacceptable in many high-pressureboiler systems.The efficiency of dissolved oxygen removalfrom boiler feedwater by chemical or mechanical means,orboth,is determined by measuring the concentration before andafter the process.The measurement is also made to check forair leakage into
10、the boiler system.5.2 The oxygen treatment method for boiler corrosionreduction requires injection of oxygen into the boiler feedwa-ter.The resulting oxygen level is monitored for controlpurposes.6.Interferences6.1 Color,turbidity,and oxidizing impurities interfere inthis test method to yield high r
11、esults.If the sample is coloredor turbid or contains oxidizing impurities,the amount ofinterference that may be contributed by such effects must bedetermined independently prior to using this test method.6.2 Easily reduced metal ions may interfere in this testmethod to cause high results.For example
12、,100 g/L(ppb)Cu+2may appear as 5 g/L(ppb)dissolved oxygen,and 100g/L Fe+3may appear as 7 g/L dissolved oxygen.However,less than 50 g/L Cu+2or Fe+3cause less than 1-g/Linterference.1These test methods are under the jurisdiction of ASTM Committee D19 onWater and are the direct responsibility of Subcom
13、mittee D19.03 on Sampling Waterand Water-Formed Deposits,Analysis of Water for Power Generation and ProcessUse,On-Line Water Analysis,and Surveillance of Water.Current edition approved Feb.1,2015.Published May 2015.Originallyapproved in 1994.Last previous edition approved in 2009 as D5543 09.DOI:10.
14、1520/D5543-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Spokes,G.N.,Dissolved Oxygen in Water Measurement a
15、nd Standardization,EPRI PWR Plant Chemists Meeting,San Diego,CA,Nov.1720,1992.Copiesobtainable from CHEMetrics Inc.,4295 Catlett Rd.,Midland,VA 22728,https:/.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.3 Hydrogen peroxide alone in c
16、oncentrations up to 200g/L does not affect the measurement of 1.4 g/L of dissolvedoxygen.Above 200 g/L hydrogen peroxide,there is a positiveinterference of 3.3 g/L dissolved oxygen per 100 g/L excessover 200 g/L hydrogen peroxide.6.4 The following interferences occur in the presence of2200 mg/L boron present as boric acid:(1)at pH levels belowpH 6,recovery can be as low as 80%;(2)added hydrogenperoxide at a concentration of 0.1 mg/L yields a positiveinterference of 10 g/L dissolved oxygen;and(3)
