ASTM E300-2003 Standard Practice for Sampling Industrial Chemicals《工业化学品抽样的标准规程》.pdf

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1、Designation: E 300 03Standard Practice forSampling Industrial Chemicals1This standard is issued under the fixed designation E 300; 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 parentheses i

2、ndicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This practice covers procedures for sampling severalclasses of industrial ch

3、emicals. It also includes recommenda-tions for determining the number and location of such samples,to ensure their being representative of the lot in accordancewith accepted probability sampling principles.1.2 Although this practice describes specific procedures forsampling various liquids, solids,

4、and slurries, in bulk or inpackages, these recommendations only outline the principles tobe observed. They should not take precedence over specificsampling instructions contained in other ASTM product ormethod standards.1.3 These procedures are covered as follows:SectionsStatistical Considerations 7

5、-11Simple Liquids 12-27Solids 28-35Slurries 36-411.4 This standard does not 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 re

6、gulatory limitations prior to use. Specific precau-tionary statements are given in Sections 6, 19, 20, 30, 34 and37.2. Referenced Documents2.1 ASTM Standards:D 270 Method of Sampling Petroleum and Petroleum Prod-ucts2D 2234 Test Methods for Collection of a Gross Sample ofCoal3E 180 Practice for Dete

7、rmining the Precision of ASTMMethods for Analysis and Testing of Industrial Chemicals43. Terminology3.1 Definitions:3.1.1 simple liquida single-phase liquid having a Reidvapor pressure of less than 110 kPa at 37.8C (16 psi at 100F)and a Saybolt viscosity of less than 10 000 s (2160 cSt) at25C.3.1.2

8、lota discreet quantity of material. It may contain asingle batch or several batches, or be the product of continuousprocess broken into units on the basis of time or shipment. It isvery desirable that individual batches in a lot be specificallyidentified so that they may become individual or stratif

9、ied unitsfor inspection.3.1.3 average sampleone that consists of proportionateparts from all sections of the container.3.1.4 spot samplea sample taken at a specific location ina tank or from a flowing stream in a pipe at a specific time.3.1.5 composite samplea blend of spot samples mixed inproportio

10、n to the volumes of material from which the spotsamples were obtained.3.1.6 all-levels sampleone obtained by submerging aclosed sampler to a point as near as possible to the draw-offlevel, then opening the sampler and raising it at a rate such thatit is about three fourths full as it emerges from th

11、e liquid. Anall-levels sample is not necessarily an average sample becausethe tank volume may not be proportional to the depth andbecause the operator may not be able to raise the sampler at thevariable rate required for proportionate filling. The rate offilling is proportional to the square root of

12、 the depth ofimmersion.NOTE 1The tube sampling procedure, 26.3, may be used to obtain anall-levels sample from a drum.3.1.7 upper samplea spot sample obtained from themiddle of the upper third of the tank contents (Fig. 1).NOTE 2The taking of samples from various levels of the tank permitsthe detect

13、ion of variation in composition of the contents caused bystratification. If it is known that the contents are not subject to this1This practice is under the jurisdiction of ASTM Committee E15 on Industrialand Specialty Chemicals and is the direct responsibility of Subcommittee E15.01 onGeneral Stand

14、ards.Current edition approved April 10, 2003. Published June 2003. Originallyapproved in 1966. Last previous edition approved in 1992 as E 300 92 (1996).Discontinued 2001. Reinstated as E 300 03.2Discontinued, see 1983 Annual Book of ASTM Standards , Vol 05.01.3Annual Book of ASTM Standards, Vol 05.

15、05.4Annual Book of ASTM Standards, Vol 15.05.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.variation, the taking of samples at multiple levels may be eliminated.3.1.8 middle samplea spot sample obtained from themiddle of the tank c

16、ontents (Fig. 1)(Note 2).3.1.9 lower samplea spot sample of liquid from themiddle of the lower one-third of the tanks content (a distanceof one-half of the depth of liquid below the liquids surface)(Fig. 1).3.1.10 single-tank composite samplea blend of the upper,middle, and lower samples. For a tank

17、 of uniform cross section,such as an upright cylindrical tank, the blend consists of equalparts of the three samples. For a horizontal cylindrical tank, theblend consists of the three samples in the proportions shown inTable 1.3.1.11 compartment-tank composite sample (ship, barge,etc.)a blend of ind

18、ividual all-levels samples from eachcompartment, which contains the product being sampled, inproportion to the volume of material in each compartment.3.1.12 top samplea spot sample normally obtained 150mm (6 in.) below the top surface of the tank contents (Fig. 1).3.1.13 outlet samplea spot sample n

19、ormally obtained withthe inlet opening of the sample apparatus at the level of thebottom of the tank outlet (either fixed or a swing line outlet)(Fig. 1).3.1.14 continuous samplea spot sample obtained from apipeline conveying the product in such a manner as to give arepresentative average of the str

20、eam throughout the period oftransit.3.1.15 jar samplea spot sample obtained by placing a jarinto the path of a free-flowing stream so as to collect a definitevolume from the full cross section of the stream.3.1.16 mixed samplea spot sample obtained after mixingor vigorously stirring the contents of

21、the original container, andthen pouring out or drawing off the quantity desired.3.1.17 tube or thief samplea spot sample obtained with asampling tube or special thief, either as a core sample or spotsample from the specified point in the container.3.1.18 drain samplea spot sample obtained from thedr

22、aw-off or discharge valve. Occasionally, a drain sample maybe the same as a bottom sample, as in the case of a tank car.3.1.19 bottom samplea spot sample obtained from thematerial on the bottom surface of the tank, container, or line atits lowest point (Fig. 1). (Drain and bottom samples are usually

23、taken to check for water, sludge, scale, etc.).3.1.20 laboratory samplethat portion of the sample whichis sent for laboratory testing.4. Summary of Practice4.1 This practice describes procedures to be followed forobtaining samples of several classes of industrial chemicals. Itaddresses in detail the

24、 various factors which need to beconsidered to obtain a representative laboratory sample. Thispractice also covers the statistical considerations in sampling ofindustrial chemicals whether they are liquids, solids or slurriesin bulk or in packages.5. Significance and Use5.1 Representative samples of

25、 industrial chemicals are re-quired for the determination of chemical and physical proper-ties which are used to establish standard volumes, prices, andcompliance with commercial and regulatory specifications.5.2 The objective of sampling is to obtain a small portion(spot sample) of material from a

26、selected area within acontainer which is representative of the material in the area or,in the case of running or all-level samples, a sample whosecomposition is representative of the total material in thecontainer. A series of spot samples may be combined to createa representative sample.5.3 Manual

27、and Automatic Sampling ConsiderationsTheselection of manual or automatic sampling devices is part ofestablishing a sampling plan applied under all conditionswithin the scope of this practice provided that the propersampling procedures are followed. Both types of sampling arecommonly used for liquid,

28、 solid, and slurry sampling andrequire adherence to the following:5.3.1 An adequate frequency of sampling must be selected.5.3.2 The equipment to support manual or automatic sam-pling systems may be obtained commercially, fabricated fromthe designs presented in this practice, or constructed as neede

29、dto satisfy process design or other specific requirements.5.3.3 The sampling equipment must be maintained on aregular basis, and the sampling plan adopted must be strictlyfollowed.FIG. 1 Sampling DepthsTABLE 1 Sampling Instructions for Horizontal Cylindrical TanksLiquid Depth,Percent ofDiameterSampl

30、ing Level, Percent ofDiameter Above BottomComposite SampleProportionate Parts ofUpper Middle Lower Upper Middle Lower100 80 50 20 3 4 390 75 50 20 3 4 380 70 50 20 2 5 370 . 50 20 1 5 460 . 50 20 . 5 550 . 40 20 . 4 640 . . 20 . . 1030 . . 15 . . 1020 . . 10 . . 1010 . . 5 . . 10E3000326. Safety Pre

31、cautions6.1 This practice covers procedures and sampling equip-ment used to sample industrial chemicals that may be poten-tially hazardous to personnel or the environment. Accordingly,it is emphasized that all applicable safety rules, regulations,and procedures must be followed in handling and proce

32、ssingthe chemicals. Furthermore, this practice does not purport tocover all safety aspects associated with sampling. However, itis presumed that the personnel performing sampling operationsare adequately trained with regard to safe application of theprocedures contained herein for the specific sampl

33、ing situation.6.2 The characteristics of the material to be sampled willgovern the type of protective equipment required. Sincesampling may present such hazards as splashing or spilling,protective clothing must be worn when the chemical is capableof producing eye or skin irritation or burns. During

34、suchpotential exposures, chemical-type goggles or face shield andprotective gloves, or combination thereof, must be worn.6.3 Respiratory protection, where required, must be in goodcondition and must be suitable to protect against chemicalsbeing handled.6.4 When sampling chemicals that may be dangero

35、us to lifeby skin absorption, oral ingestion, or by breathing the vapor,unusual precautions will be indicated. In such cases, full-bodyprotection such as supplied by a gas-tight or one-piece air-supplied suit should be worn. A second person must becontinuously present to summon help and render aid i

36、n theevent of an emergency.STATISTICAL CONSIDERATIONS57. Objectives7.1 The sampling and testing of industrial chemicals mayhave one or more of the following objectives:7.1.1 The objective may be to estimate the average qualitycharacteristic of a given lot of material and to establishconfidence limit

37、s for this average. This would be the mainobjective, for example, if a dollar value is to be placed on thematerial for customs purposes or for sale.7.1.2 The objective may be to decide whether the averagevalue for the lot meets a specification. This calls for anacceptance sampling plan with the crit

38、erion being related to theestimated mean of the lot.7.1.3 The objective may be to estimate or make decisionsabout the variability of a quality characteristic within the lot.7.1.4 The objective may be to obtain simultaneous estimatesof the mean and variance or to make decisions about some jointcombin

39、ation of these estimates.7.1.5 If the material comes in containers or can be viewed ascoming in clearly demarked units, the objective may be that ofestimating the number of such units outside of specifications,that is, the “fraction defective.”NOTE 3Procedures are given below for estimating average

40、qualityand for applying acceptance sampling inspection based on the lot mean.8. General Sampling Considerations8.1 To obtain samples that are representative in a statisticalsense, one must consider such factors as physical form,uniformity, type and number of containers, etc. All of thesefactors infl

41、uence the choice of method for performing thesampling operation, as well as the number and location of therequired samples. Two commonly used practices for selectingthe sequence or location of the individual samples are de-scribed.8.2 Random Sampling is achieved when every part of thelot has an equa

42、l chance of being drawn into the sample.8.2.1 Designate all units in the lot, choosing numbers insequence or other serial code so that sampling by randomnumbers can be employed.8.2.2 Preferably, this sequence should be in direct relation toorder of manufacture of packaging as an aid to observing, fr

43、omthe sample results, any evidence of stratification.8.2.3 Random selection of the numbers should be accom-plished by chance or preferably by the use of a table of randomnumbers.8.3 Stratified Sampling can be employed to estimate aver-age quality when it is known or suspected that the value of aprop

44、erty of the material varies in non-random fashion through-out the lot for the following typical reasons: (a) the lot maycontain several production batches, (b) the lot may containunits produced by different procedures, equipment, shifts, etc.,or (c) the lot may be non-uniform because of subsequent s

45、izesegregation, moisture pickup, surface oxidation, etc. If theassumed pattern is correct, the variance of the population meanestimate will be less than that based on random sampling. If theassumptions are incorrect, the estimate of the mean may bebiased. A stratified sample can be obtained as follo

46、ws:8.3.1 Based on the known or suspected pattern, divide thelot into a number of real or imaginary strata.8.3.2 If these sections are not equal in size, the number ofsamples to be taken from each stratum must be proportional tothe size of the various strata.8.3.3 Further subdivide the major strata i

47、nto real or imagi-nary subsections and select the required number of samples bychance or preferably by means of a table of random numbers.9. Estimate of Average Quality9.1 Determination of the Variance of a Sample MeanIfthe material comes in, or can be viewed as coming in,realizable primary units, e

48、ach of which are to be divided intorealizable secondary units, and if nbprimary units are selectedat random from a lot of N primary units, and if nwsecondaryunits are selected from each primary unit with k tests beingmade on each secondary unit drawn, then the variance of themean of the results is g

49、iven as follows (Note 4 and Note 5):sx25 sb2/nb! 3 N 2 nb!/N 1 sw2/nb3 nw!# 1 st2/nt! (1)where:sx2= variance of the mean,sb2= variance of primary units (the material in cars,tanks, cans, drums, bottles, or other containers) inthe lot,5Prepared by an Ad Hoc Committee of ASTM Committee E11 on StatisticalMethods.E300033sw2= average variance of secondary units (all-level, tube,thief, or similar samples) from a primary unit,st2= variance of tests on a homogeneous sample,N = number of primary units in the lot,nb= number of randomly selected primary un