1、Designation: D5544 11Standard Test Method forOn-Line Measurement of Residue After Evaporation of High-Purity Water1This standard is issued under the fixed designation D5544; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、of last revision. A number 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 dissolvedorganic and inorganic matter and colloidal material found inh
3、igh-purity water used in the semiconductor, and relatedindustries. This material is referred to as residue after evapo-ration (RAE). The range of the test method is from 0.001g/L(ppb) to 60 g/L (ppb).1.2 This test method uses a continuous, real time monitoringtechnique to measure the concentration o
4、f RAE. A pressurizedsample of high-purity water is supplied to the test methodsapparatus continuously through ultra-clean fittings and tubing.Contaminants from the atmosphere are therefore preventedfrom entering the sample. General information on the testmethod and a literature review on the continu
5、ous measurementof RAE has been published.21.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
6、the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardsstatements, see Section 8.2. Referenced Documents2.1 ASTM Standards:3D1129 Terminology Relating to WaterD2777 Practice for Dete
7、rmination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3864 Guide for Continual On-Line Monitoring Systemsfor Water AnalysisD3919 Practice for Measuring Trace Elements in Water byGraphite Furnace Atomic Absorption Sp
8、ectrophotometryD5127 Guide for Ultra-Pure Water Used in the Electronicsand Semiconductor IndustriesE1184 Practice for Determination of Elements by GraphiteFurnace Atomic Absorption Spectrometry3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D1129.3
9、.2 Definitions of Terms Specific to This Standard:3.2.1 aerosol, nany solid or liquid particles, with anominal size range from 10 nm to 100 m, suspended in a gas(usually air).3.2.2 colloidal suspension, nany material in suspension(for example, silica) with a nominal particle size less than 100nm.3.2
10、.3 Water-based condensation particle counter (WCPC),ninstrument for detecting very small aerosol particles in asize range from approximately 7 nm to 2 to 3 m.3.2.3.1 DiscussionThe WCPC cannot differentiate amongparticles of varying size within this size range; the counterreports the number of partic
11、les with a size greater than thatdefined by the detection-efficiency curve. Detection is indepen-dent of particle composition.3.2.4 detection effciency, nin this test method, detectionefficiency represents a curve relating particle size to a countersability to detect that size.3.2.5 polydisperse, ad
12、ja type of size population, in thiscase of aerosol particles, composed of many different sizes; theopposite of monodisperse, which is a type of size distributionof just one size.3.2.6 realtime, nthe time that an event is occurring plusthe response time.1This test method is under the jurisdiction of
13、ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits, Analysis of Water for Power Generation and Process Use,On-Line Water Analysis, and Surveillance of Water.Current edition approved May 1, 2011. Published May 2011. Originally
14、approved in 1994. Last previous edition approved in 2005 as D5544 05. DOI:10.1520/D5544-11.2Blackford, D. B., “Use of Nonvolatile Residue Monitoring in SemiconductorWater Applications” Ultrapure Water Journal, November 2008 pp 16-23 Publishedby Tall Oaks Publishing3For referenced ASTM standards, vis
15、it 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2
16、959, United States.3.2.6.1 DiscussionIn this case, the response time is 3 to 5min, therefore, contamination is recorded 3 to 5 min after itoccurs.3.2.7 residue after evaporation, ncontaminants remainingafter all water is evaporated; sometimes known as nonvolatileresidue or total dissolved and suspen
17、ded solids.4. Summary of Test Method4.1 This test method consists of continuously removing arepresentative sample of high-purity water from a pressurizedsupply line (refer to Practices D3370, Practice C on ContinualSampling, and Practice D3864). The temperature of the incom-ing high-purity water sho
18、uld ideally be at room temperature,but not more than 50C. A nebulizer is supplied with thehigh-purity water at a constant flow rate, and a source ofcompressed air, or nitrogen, at a constant flow rate andpressure, to generate a stable aerosol of high-purity waterdroplets. Under these conditions, the
19、 nebulizer produces apolydisperse size distribution of droplets with a median size ofapproximately 1 m, and a concentration of approximately 107droplets/s, or 1012droplets/mL4.2 The droplets are heated at 120C. . After the heating,additional compressed air or nitrogen is introduced from thesupply to
20、 prevent re-condensation and to quickly move theresidue particles to the Water-based Condensation ParticleCounter (WCPC).4.3 The WCPC works as follows: Residue particles passthrough a region called the Saturator (see Fig. 1) where theresidue particles are saturated with water vapor and tempera-ture
21、equilibrated. The residue particles and water vapor thenpass into a region called the Growth Tube, where the wettedwalls of the porous media are heated to raise vapor pressure.The high diffusivity of the vapor allows it to reach the centerof the sample stream at a faster rate than the thermal diffus
22、ivityof the vapor can equilibrate to the higher temperatures near thewalls, resulting in a supersaturated condition along the radiusof the flow stream. Residue particles in the flow stream act asnuclei for condensation. Water condenses on the residueparticles to form large droplets with only one res
23、idue particle atthe center of each droplet. Droplets can then be counted with arelatively simple optical particle counter. A more elaborateFIG. 1 Schematic Diagram of Apparatus Required for This Test MethodD5544 112description of the WCPCs method for distinguishing betweenclean and dirty water is de
24、scribed in Appendix X1.4.4 A calibration technique (described in detail in Section10) uses concentration standards of high-purity potassiumchloride (KCl) to convert the WCPC count concentration inparticles per cubic centimetre into RAE concentration inmicrograms per litre or milligrams per litre.Agr
25、aphite furnaceatomic absorption spectrometer (GFAAS), or equivalentmethod, can be used to check the concentration of KCl in thistest method standard (see Practices D3919 and E1184).5. Significance and Use5.1 Even so-called high-purity water will contain contami-nants. While not always present, these
26、 contaminants maycontribute one or more of the following: dissolved active ionicsubstances such as calcium, magnesium, sodium, potassium,manganese, ammonium, bicarbonates, sulfates, nitrates, chlo-ride and fluoride ions, ferric and ferrous ions, and silicates;dissolved organic substances such as pes
27、ticides, herbicides,plasticizers, styrene monomers, deionization resin material;and colloidal suspensions such as silica. While this test methodfacilitates the monitoring of these contaminants in high-puritywater, in real time, with one instrument, this test method is notcapable of identifying the v
28、arious sources of residue contami-nation or detecting dissolved gases or suspended particles.5.2 This test method is calibrated using weighed amounts ofan artificial contaminant (potassium chloride). The density ofpotassium chloride is reasonably typical of contaminants foundin high-purity water; ho
29、wever, the response of this test methodis clearly based on a response to potassium chloride. Theresponse to actual contaminants found in high-purity watermay differ from the test methods calibration. This test methodis not different from many other analytical test methods in thisrespect.5.3 Together
30、 with other monitoring methods, this testmethod is useful for diagnosing sources of RAE in ultra-purewater systems. In particular, this test method can be used todetect leakages such as colloidal silica breakthrough from theeffluent of a primary anion or mixed-bed deionizer. In addition,this test me
31、thod has been used to measure the rinse-up time fornew liquid filters and has been adapted for batch-type sampling(this adaptation is not described in this test method).5.4 Obtaining an immediate indication of contamination inhigh-purity water has significance to those industries usinghigh-purity wa
32、ter for manufacturing components; productioncan be halted immediately to correct a contamination problem.The emerging nano-particle technology industry will alsobenefit from this information.6. Apparatus6.1 The schematic arrangement of the system is shown inFig. 1. The apparatus is available as a co
33、mplete instrument4.6.2 2 60 m Filter, high purity water flows into the appara-tus at approximately 120 mL/min and immediately passesthrough a 60 m sintered stainless filter that removes any largedebris and then flows to flow controller.6.3 Flow Controller, made of a non-contaminating materialsuch as
34、 perfluoroalkoxy (PFA), necessary to supply the nebu-lizer with high-purity water at the desired flow rate. The flowcontroller must contain an air actuated pressure regulator toensure that water is delivered to the nebulizer at a stable flowrate, despite external fluctuations. High-purity water must
35、 bedelivered to the flow controller and nebulizer through ultra-clean tubes and fittings made from PFA. Nebulizers usuallyrequire a very low flow rate, approximately 1 mL/min, forefficient operation. However, such a low flow rate is inadequatefor routine monitoring because it results in a long respo
36、nsetime. This test method is designed to overcome the problem oflong response times by using a flow controller to deliverapproximately 120 mL/min of high-purity water to the moni-toring site and then to divert approximately 1 mL/min of theflow to the nebulizer through a short tube. This short tubefa
37、cilitates a short response time. From the pressure regulator,the water flows to the nebulizer through a tee fitting and asection of PFA 500m capillary tubing. The PFA tubinggradually lowers the water pressure and prevents any out-gassing of dissolved gases in the incoming water.6.4 Measuring the Flo
38、w Rate, the flow rate of water flowingthrough the nebulizer is used as an indicator that the NRM8000 is set up and operating correctly. Instead of using aconventional flow meter, the NRM 8000 incorporates a new,patented method of measuring the flow rate. Of the waterflowing through the nebulizer, 95
39、% leaves it as part of a wastestream. The waste water is collected by a weir and stand-pipesystem and then delivered as a steady stream of water dropletsof identical size. These droplets fall through a simple lightbeam. As each droplet breaks the beam, a detector senses ascattered light signal, or p
40、ulse, and a counter keeps track of thepulses. An algorithm converts the pulse count to a flowrate (inmL/min.) which is shown on the front panel display.6.5 Nebulizer, required to produce a polydisperse sizedistribution of droplets with a median size of approximately 1m and a concentration of approxi
41、mately 107droplets/s.Within the customed designed nebulizer, the water and com-pressed air/nitrogen (supplied at a constant flow rate andpressure) combine to form the required stable, poly-dispersedaerosol of ultrapure water droplets. The nebulizer must besupplied with clean, dried filtered compress
42、ed air or nitrogenand must be machined from a material that will not contami-nate the high-purity water. Passivated 316L stainless steel hasbeen used successfully in this test method. Details of how topassivate stainless steel can be found in the Metal FinishingGuidebook.56.6 Heater and Dilution air
43、/nitrogen, the ultrapure waterdroplets produced by the nebulizer are rapidly heated at 120C.Each water droplet is evaporated to dryness, leaving behind aparticle of residue consisting of dissolved inorganic material.Every nebulizer droplet results in a residue particle: the cleaner4The sole source o
44、f supply of the apparatus known to the committee at this timeis Fluid Measurement Technologies, 4106 Hoffman Road, White Bear Lake, MN55110. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation
45、 at a meeting of the responsible technical committee1, which you may attend.5Metal Finishing Guidebook, Elsevier Science, New York, NY, 60th ed., 1992.D5544 113the ultrapure water, the smaller the amount of residue withineach droplet, and the smaller the resulting residue particle.After the heating,
46、 additional compressed air or nitrogen, isintroduced from the supply to prevent re-condensation and toquickly move the residue particles to the Water-based Conden-sation Particle Counter (WCPC).6.7 Water-based Condensation Particle Counter (WCPC),The WCPC uses a patented technology to count residuep
47、articles. Water is used as the working fluid and mixing oradiabatic expansion techniques are not needed.Acondensationnucleation technique deposits water on the residue particles togrow them to a size that can be detected with a conventionaloptical counting system. The stream of residue particles isu
48、ninterrupted and follows a laminar flow path from the sampleinlet to the optical detector. The WCPC particle countingprocess is as follows:(1) The residue particles are mixed with water vapor in theSaturator and then temperature equilibrated.(2) The residue particles pass to a growth tube where thew
49、etted walls (composed of a porous ceramic medium) areheated to raise the vapor pressure. The high diffusivity of thewater vapor allows the vapor to reach the center of the samplestream at a faster rate than the thermal diffusivity of the vaporcan equilibrate to the higher temperatures near the walls creating a supersaturated condition along the radius of the flowstream. These unstable conditions facilitate water condensationon the residue particles.(3) The residue particles that are larger than the detectionlimit of the WCPC particle critical size act a
