1、BRITISH STANDARDSoil quality Determination of soil water content as a volume fraction using coring sleeves Gravimetric methodICS 13.080.05NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN ISO 11461:2014National forewordThis British Standard is the UK implementation of EN IS
2、O 11461:2014. It is identical to ISO 11461:2001. It supersedes BS ISO 11461:2001, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee EH/4, Soil quality.A list of organizations represented on this committee can be obtained on request to its secretary.A Bri
3、tish Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BS EN ISO 11461:2014This British Standard, havingbeen prepar
4、ed under thedirection of the Health andEnvironment Sector Policy andStrategy Committee, waspublished under the authorityof the Standards Policy andStrategy Committee on3 September 2001Amendments/corrigenda issued since publicationDate Comments 31 July 2014 This corrigendum renumbers BS ISO 11461:201
5、1 as BS EN ISO 11461:2014ISBN 978 0 580 82152 3 The British Standards Institution 2014. Published by BSI Standards Limited 2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11461 March 2014 ICS 13.080.40 English Version Soil quality - Determination of soil water content as a volume fracti
6、on using coring sleeves - Gravimetric method (ISO 11461:2001) Qualit du sol - Dtermination de la teneur en eau du sol en fraction volumique, laide de carottiers - Mthode gravimtrique (ISO 11461:2001) Bodenbeschaffenheit - Bestimmung des Wassergehaltes des Bodens als Volumenanteil mittels Stechzylind
7、er - Gravimetrisches Verfahren (ISO 11461:2001) This European Standard was approved by CEN on 13 March 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any altera
8、tion. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made
9、by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia
10、, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDAR
11、DIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11461:2014 Eii Foreword The text of IS
12、O 11461:2001 has been prepared by Technical Committee ISO/TC 190 “Soil quality” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 11461:2014 by Technical Committee CEN/TC 345 “Characterization of soils” the secretariat of which is held by NEN. This Europea
13、n Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2014, and conflicting national standards shall be withdrawn at the latest by September 2014. Attention is drawn to the possibility that some of the el
14、ements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this
15、European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,
16、 Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 11461:2001 has been approved by CEN as EN ISO 11461:2014 without any modification. BS EN ISO 11461:2014 EN ISO 11461:2014 (E)iiiContents Page1 Scope . 12 Terms and definitions 13 Symbols 14 Princ
17、iple 25 Apparatus . 26 Field sampling 27 Procedure . 38 Expression of results 39 Accuracy and precision 410 Test report 5Bibliography. 6BS EN ISO 11461:2014 ISO 11461:2001 (E)This page deliberately set blankINTERNATIONAL STANDARD1Soil quality Determination of soil water content as a volumefraction u
18、sing coring sleeves Gravimetric method1 ScopeThis International Standard specifies a method for the gravimetric determination of soil water content as a volumefraction.The method is applicable to all types of non-swelling or non-shrinking soils where coring sleeves can be used forsampling. It is not
19、 applicable to soils where stones, tough roots or other factors prevent collection of soil cores. It isused as a reference method (e.g. the calibration of indirect methods for determination of water content).NOTE The determination of water content as a mass fraction is described in ISO 11465.2 Terms
20、 and definitionsFor the purposes of this International Standard, the following terms and definitions apply.2.1water content volume fractionvolume of water evaporating from the soil when dried to constant mass at , divided by the original bulk volumeof the soilNOTE The water content volume fraction i
21、s sometimes also referred to as “volumetric water content”.2.2constant massmass reached when during the drying process the difference between two successive weighings of the sample, aftera drying interval of , does not exceed (mass fraction) of the last determined massNOTE Usually to is sufficient f
22、or drying most soils to constant mass, but certain soil types and large or very wetsamples will require longer.3Symbolsmass, expressed in kilogramsvolume, expressed in cubic metressample standard deviation of variablestandard deviation of the errors in variablewater content volume fractiondensity of
23、 water, expressed in kilograms per cubic metre ( )105C4 h 0,1 %16 h 24 hmVsxxxxwkg m3ISO 11461:2001 (E)24PrincipleSoil samples of known volume are dried to constant mass at . The difference in the mass of the soilsample, before and after the drying procedure, is taken as a measure of the water conte
24、nt. The water content iscalculated as a volume fraction.NOTE Organic matter can oxidize during drying. This has no significant effect on the water content determined. However, dryingat lower temperatures, e.g. , can lead to significantly lower values of the water content. Hence, drying at a temperat
25、ure lowerthan is not recommended.5 Apparatus5.1 Drying oven, thermostatically controlled with forced air ventilation and capable of maintaining a temperature of. Differences in temperature between various positions in the oven shall be less than .NOTE By measuring the temperature at the centre of a
26、sample during or directly after the drying procedure using a thinthermocouple with low thermal capacity, it is possible to determine whether the oven is working efficiently. These measurementsshould be carried out on dry samples, to prevent temperature differences due to evaporation.5.2 Desiccator w
27、ith an active drying agent.5.3 Balance, capable of weighing accurately to within of the mass of the dried sample.5.4 Coring sleeves, of known volume, fitted with water- and vapour-tight caps of known mass to preventevaporation of water from the samples.Each sleeve shall have a sharp cutting edge or
28、shall be used with a holder with a sharp cutting edge. The volume ofeach coring sleeve shall be greater than . The precise dimensions of the coring sleeves will depend on thegoal of the investigation.5.5 Pushing rod, for the coring sleeves.5.6 Dishes of known mass, to support the soil in the coring
29、sleeves while handling them in the laboratory.6 Field sampling6.1 GeneralFor the direct determination of water content volume fraction, a sample of known volume is required and coringsleeves are therefore used for sample collection.The size of the coring sleeves and the number of samples required wi
30、ll be governed by the objectives of theinvestigation and usually the need to represent the soil more generally; one should take into account the size of thestructural elements of the soil and its variability.Samples shall be collected, transported and stored so that their water content does not chan
31、ge from that at the timeof sampling.6.2 Sampling procedureIn the field, take the soil samples by pushing coring sleeves (5.4) into the soil either directly or using a holder. Extracteach soil-filled sleeve carefully from the soil. Trim any soil protruding from the sleeve using a straight knife. Disc
32、ardsoil cores that are either compacted or incomplete. The pushing rod (5.5) may be used for sampling at depth. Coverboth ends of the coring sleeves. Use water- and vapour-tight caps (5.4), in order to prevent evaporation of waterduring transport to the laboratory.(105 5)C60C105C(105 5)C 5C0,1 %20 c
33、m3BS EN ISO 11461:2014 ISO 11461:2001 (E)37 ProcedureCAUTION With samples from contaminated soils, avoid any contact with the skin and use ventilation andextraction during the drying process to prevent contamination of the laboratory atmosphere and othersamples.7.1 Using the balance (5.3), determine
34、 the mass, , of the soil-filled coring sleeve with caps as soon as possibleafter sampling, to prevent errors due to evaporation of soil water.7.2 Remove the upper cap. Place a dish of known mass (5.6; or similar device) on the sleeve to support the soil.Turn over the sample and remove the other cove
35、r. Ensure that no soil remains on the caps. If necessary, transfer thatsoil to the soil in the coring sleeve. Place the coring sleeve with dish in the drying oven. Ensure that the oven is set toa temperature of . Ensure that the water vapour can escape and that the temperature does not vary more tha
36、nthroughout the oven. Let the sample dry for at least .7.3 Take the soil-filled coring sleeve with dish out of the oven and place them in a desiccator (5.2) containing anactive drying agent. Transport the desiccator to the balance (5.3). Determine the mass of the soil-filled coring sleevewith dish.7
37、.4 Replace the soil-filled coring sleeve with dish in the oven for an additional and repeat the drying-weighingprocedure until the difference in two successive weighings does not exceed of the last determined mass of thedried sample, .8 Expression of resultsCalculate the total mass of the field-wet
38、soil, sleeve and dish:whereis the mass of the caps, in kilograms;is the mass of the dish, in kilograms;is the total mass of the field-wet soil, sleeve and caps, in kilograms;is the total mass of the field-wet soil, sleeve and dish, in kilograms.The water content volume fraction is given by the equat
39、ion:whereis the water content volume fraction;is the total mass of the oven-dry soil, sleeve and dish, in kilograms;is the total mass of the field-wet soil, sleeve and dish, in kilograms;is the density of water at soil temperature, in kilograms per cubic metre;is the volume of the coring sleeve, in
40、cubic metres.mtot0105C5C164h0,1 %mtot1mtot2= mtot0mcap+mdishmcapmdishmtot0mtot2=mtot2mtot1wVmtot1mtot2wVBS EN ISO 11461:2014 ISO 11461:2001 (E)49 Accuracy and precision9.1 GeneralIn the procedure stated for the determination of volumetric water content, the main factors that may influence thewater c
41、ontent measurement are sampling, transport, laboratory treatment and density of water.9.2 Samplinga) Compaction and/or disturbance of the sample may influence the measurement. Various factors including thecompressibility of the soil, the presence of stones and the sharpness of the cutting edge influ
42、ence whether asample is disturbed and/or compacted to some extent during sampling. These factors may cause variable and/orsystematic errors in time and space. The variable (i.e. coincidental) error component occurs in time and space( , ) with respect to : . Systematic errors may occur and if possibl
43、e, a correction should beestablished for these. The uncertainty in this correction should then be applied as the final systematic error,hence: corr. .b) A deviation in the sample volume due to imperfect cutting of the sample results in a variable error of the type.c) Poor precision of the volume of
44、the sample sleeve may influence the measurement. One should establish acorrection for this effect, hence: corr. .9.3 TransportEvaporation of water from moist soil samples or sorption of water from the air by relatively dry samples may occurdue to poor closure of the coring sleeve caps and/or a too l
45、ong period for transport or storage. The susceptibility ofthe sample to such water content changes is influenced by its water content. It results in a correction as in 9.2 a),hence: corr. .9.4 Laboratory analysisa) Poor precision of the weighing balance results in a variable error in both weighings,
46、 hence: and.b) Weighing errors in the mass of dishes and caps result in systematic errors in , hence corr. .c) Loss of sample mass, due to soil grains sticking to the caps when removing them, results in a variable error in,hence .d) Volatilization of substances other than water on heating at may inf
47、luence the measurement. In soilswhere this process is important, establish a correction for the effect, hence: corr. .e) Sorption of moist air, due to too long a time between removing the sample from the desiccator and the secondweighing, also calls for a correction: corr. .9.5 Density of waterA dev
48、iation in water density as a consequence of temperature differences between the field and the laboratoryresults in a correction of the type corr. .After estimation of the standard deviation of the respective error sources, their propagation in the water content canbe estimated with the following for
49、mula:tx mtot2mtot2(t,x)mtot2V(t,x)Vmtot2mtot1(t,x)mtot2(t,x)mtot2mtot2mtot1mtot1(t,x)105Cmtot2mtot1ws= 3s1wV2parenleftbigs2mtot1+s2mtot2+wV2parenleftbigV2s2w+ 2ws2VBS EN ISO 11461:2014 ISO 11461:2001 (E)5whererepresents the standard deviation of the errors influencing the water content volume fraction;represents the standard deviation of the errors influencing ;represents the standard deviation of the errors influencing ;represents the standard deviation of the errors influencing ;represents the standard deviation of the errors influencing .In the final results o
