1、May 2012 Translation by DIN-Sprachendienst.English price group 8No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 13.
2、080.40!$|.“1892711www.din.deDDIN ISO 16586Soil quality Determination of soil water content as a volume fraction on the basis ofknown dry bulk density Gravimetric method (ISO 16586:2003 + Cor. 1:2009)English translation of DIN ISO 16586:2012-05Bodenbeschaffenheit Bestimmung des Wassergehaltes des Bod
3、ens als Volumenanteil auf der Grundlage derbekannten Trockenrohdichte Gravimetrisches Verfahren (ISO 16586:2003 + Cor. 1:2009)Englische bersetzung von DIN ISO 16586:2012-05Qualit du soil Dtermination de la teneur en eau volumique du sol partir de la masse volumiqueapparente sche connue Mthode gravim
4、trique (ISO 16586:2003 + Cor. 1:2009)Traduction anglaise de DIN ISO 16586:2012-05SupersedesDIN ISO 16586:2006-06www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1104.12 A comma is used as the decimal marker. Contents Page National f
5、oreword .3 National Annex NA (informative) Bibliography 3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Symbols 6 5 Principle 6 6 Apparatus .6 7 Procedure .6 8 Expression of results 6 9 Accuracy and precision 7 10 Test report 7 Annex A (informative) The accuracy of
6、w and b.8 A.1 General 8 A.2 Symbols 8 A.3 Basic sources of w error .8 A.4 Propagation of errors in w 9 A.5 Basic sources of berror .9 A.6 Propagation of errors in b10 Bibliography 11 2 DIN ISO 16586:2012-05 National foreword This standard has been prepared by Technical Committee ISO/TC 190 “Soil qua
7、lity” (Secretariat: NEN, Netherlands). The responsible German body involved in its preparation was the Normenausschuss Wasserwesen (Water Practice Standards Committee), Working Committee NA 119-01-02 AA Abfall- und Bodenuntersuchung. The DIN Standards corresponding to the International Standards ref
8、erred to in this document are as follows: ISO 11272 DIN ISO 11272 ISO 11461 DIN ISO 11461 ISO 11465 DIN ISO 11465 Amendments This standard differs from DIN ISO 16586:2006-06 as follows: a) in Clause A.6 an editorial amendment has been made; b) the standard has been editorially revised to reflect the
9、 current ISO rules for drafting; c) in Clause A.6 the explanation of the formula for calculating the “propagation of errors” has been corrected in accordance with ISO 16586:2003/Cor.1:2009; d) the standard has been editorially revised. Previous editions DIN ISO 16586: 2006-06 National Annex NA (info
10、rmative) Bibliography DIN ISO 11272, Soil quality Determination of dry bulk density DIN ISO 11461, Soil quality Determination of soil water content as a volume fraction using coring sleeves Gravimetric method DIN ISO 11465, Soil quality Determination of dry matter and water content on a mass basis G
11、ravimetric method 3 DIN ISO 16586:2012-05 Introduction The determination of water content volume fraction using coring sleeves, which is described in ISO 11461, is the basic method for determination of the water content volume fraction. This International Standard provides a less precise method than
12、 that given in ISO 11461. Soil quality Determination of soil water content as a volume fraction on the basis of known dry bulk density Gravimetric method 4 DIN ISO 16586:2012-05 1 Scope This International Standard specifies a method for the gravimetric determination of soil water content as a volume
13、 fraction on the basis of the ratio of measured water content mass to known dry bulk density. This International Standard is applicable to all types of non-swelling or non-shrinking soils. It is used as a reference method (e.g. the calibration of indirect methods for determination of water content).
14、 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 11465:1993, Soil qual
15、ity Determination of dry matter and water content on a mass basis Gravimetric method 3 Terms and definitions 3.1 water content water content mass fraction water content mass ratio ratio of the mass of water evaporating from the soil when dried to constant mass at 105 C, to the dry mass of the soil s
16、ample NOTE For soil with high content of organic matter, drying at a temperature below 70 C is usual practice. 3.2 dry bulk density mass of the solid particles divided by the undisturbed bulk volume of the soil 3.3 water content volume fraction volumetric water content ratio of the volume of water e
17、vaporating from the soil when dried to constant mass at 105 C, to the original bulk volume of the soil 5 DIN ISO 16586:2012-05 4 Symbols sxsample standard deviation of variation of variable x; w water content (mass fraction), expressed in kilograms per kilogram; xstandard deviation of the errors in
18、variable x; water content volume fraction, expressed in cubic metres per cubic metre; bdry bulk density, expressed in kilograms per cubic metre; wdensity of water, expressed in kilograms per cubic metre. 5 Principle Soil samples are dried to constant mass at 105 C. The difference in the mass of the
19、soil sample, before and after the drying procedure, is taken as a measure of the water content. The water content (mass fraction) is converted to the water content (volume fraction) by using a known value for the dry bulk density. This method is inherently less accurate than ISO 11461, since the dry
20、 bulk density is not determined on the same sample. NOTE The dry bulk density may be known from previous sampling. If the dry bulk density is not known, it can be determined in accordance with ISO 11272. 6 Apparatus Equipment for determination of water content as a mass fraction shall be in accordan
21、ce with ISO 11465. 7 Procedure Sampling, transport and laboratory treatment of the samples shall be carried out in accordance with ISO 11465. NOTE Usually larger samples are needed than those specified in ISO 11465. For structured soils, a sample including 20 structural elements is satisfactory for
22、most investigations. 8 Expression of results Calculate w in accordance with ISO 11465. Compute the water content volume fraction from: bww= where w is the water content mass fraction; is the water content volume fraction; bis the dry bulk density of the sample, in kilograms per cubic metre; 6 DIN IS
23、O 16586:2012-05 wis the density of water at soil temperature, in kilograms per cubic metre (usually an approximation of 1 000 kg m3will be satisfactory for this method) NOTE The water content (mass fraction) in accordance with ISO 11465 is expressed as a percentage. This number can be converted to a
24、 decimal fraction by dividing by 100. 9 Accuracy and precision 9.1 Various error sources influence the accuracy of the calculated water content through errors in w, band w. The basic inaccuracies due to sampling, transport and laboratory handling have to be assessed within the procedures given in IS
25、O 11465 (w) and ISO 11272 (b), as well as the final error in these variables. For convenience, a summary of the assessment of these errors is given in Annex A. 9.2 Temperature differences between the field and laboratory introduce a deviation in w. If this systematic error occurs, a correction shall
26、 be established for it. The uncertainty in this correction shall then be applied as the final systematic error, hence: corr. w. 9.3 After estimation of the standard deviation of the respective error sources in w, band w, their propagation in the water content can be estimated with the following form
27、ula: bw22 2bww wwwssss =+ where s, sw, sband sware the standard deviations of , w, band wrespectively. In the final result one may distinguish between the (total) variable component in time and space s(t,x) and the (total) systematic component s(see Annex A). General guidelines for the actual magnit
28、ude of specific error sources cannot be given, since they fully depend on sampling and laboratory practice. Apart from the error sources in bas elaborated in Annex A, the temporal and spatial variabilities in this variable shall be taken into account, due to differences in both sampling sites and sa
29、mpling times between w and b.10 Test report The test report shall include following information: a) reference to this International Standard; b) an accurate description of the sampling location and depth; c) the date of field sampling; d) the mass of the soil sample used for the determination; e) th
30、e dry bulk density value(s) used, the method used to determine the dry bulk density, the time and sites used for the dry bulk density determination(s); f) the calculated water content (volume fraction); g) details of any operations not specified in this International Standard, or regarded as optiona
31、l, as well as any other factors which may have affected the results. 7 DIN ISO 16586:2012-05 Annex A (informative) The accuracy of w and bA.1 General At present ISO 11465 and ISO 11272 do not provide for procedures for estimation of the errors in w and b. In this Annex these errors are elaborated. A
32、.2 Symbols The following new symbols are used in this Annex: m1mass of the field-moist soil sample, in kilograms; m2mass of the dried soil sample, in kilograms; sxsample standard deviation of variation of variable x; V volume of the soil sample, in cubic metres; xstandard deviation of the errors in
33、variable x. A.3 Basic sources of w error In the course of the procedures followed for determination of w, the following main causes of error are present that can influence the calculated values. a) Storage Evaporation of water from moist soil samples or sorption of water from the air by relatively d
34、ry samples can occur due to poor closure of the transport bags and/or a too long period for transport or storage. The susceptibility of the sample to such changes in water content is influenced by its initial water content. If this systematic error occurs, a correction should be established for it.
35、The uncertainty in this correction should then be applied as the final systematic error, hence: corr. m1.b) Laboratory analysis 1) poor precision of the weighing balance, which results in a variable error in weighings in both time and space (t, x), hence:m1(t,x) and m2(t,x); 2) poor precision of the
36、 weighing balance, which results in a variable error in the weighing of the moisture box used for drying the soil. This error influences the calculation of m2, hence: m2(t,x) 3) volatilization of substances other than water. Also in this case one should establish a correction for this effect, hence:
37、 corr. m18 DIN ISO 16586:2012-05 4) sorption of moist air due to a too long time gap between removing the sample from the desiccator and the second weighing. This also calls for a correction: corr. m2. 5) variations in the time and temperature of drying. A.4 Propagation of errors in w After estimati
38、on of the standard deviation of all of the respective error sources in m1and m2, their propagation in w can be estimated with the following formula: 1222212221wmmmsssmm=+where sm1and sm2are the standard deviations of the errors influencing m1and m2respectively; swis the standard deviation of the det
39、ermination of w. The formula results in total errors irrespective of their behaviour in time and/or space. One may distinguish between the (total) variable component (t,x) and the (total) systematic component , according to A.3 b) 1) to A.3 b) 5). A.5 Basic sources of berror In the course of the pro
40、cedures followed for determination of b, the following main causes are present that can influence the calculated values: a) Sampling 1) Compaction and/or disturbance of the sample. Various factors, including the compressibility of the soil, the presence of stones and the sharpness of the cutting edg
41、e influence whether a sample is disturbed and/or compacted to some extent during sampling. These factors may cause variable and/or systematic errors in time and space. The variable (i.e. coincidental) error component occurs in time and space (t,x) with respect to m2: m2(t,x). Systematic errors may o
42、ccur and if possible, a correction should be established for these. The uncertainty in this correction should then be applied as the final systematic error, hence: corr. m2. 2) Deviation in the sample volume due to imperfect cutting of the sample. This results in a variable error of the type V(t,x);
43、 3) Poor precision of the volume of the sample sleeve. One should establish a correction for this effect, hence: corr. V; b) Laboratory analysis 1) Poor precision of the weighing balance, which results in a variable error, hence: m2(t,x). 2) Volatilization of substances other than water. Also in thi
44、s case one should establish a correction for this effect, hence: corr. m2. 9 DIN ISO 16586:2012-05 3) Sorption of moist air due to a too long time gap between removing the sample from the desiccator and the second weighing. This too calls for a correction: corr. m2. A.6 Propagation of errors in bAft
45、er estimation of the standard deviation of the respective error sources in m2and V, their propagation in bcan be estimated with the following formula: b22222221Vmms ssVV=+ The formula results in total errors irrespective of their behaviour in time and/or space. One may distinguish between the (total
46、) variable component (t,x) and the (total) systematic component , according to A.5 a) and A.5.b). 10 where sm2and sVare the standard deviations of the errors influencing m2and V respectively and sbis the standard deviation of the determination of b. DIN ISO 16586:2012-05 Bibliography 1 ISO 11461:2001, Soil quality Determination of soil water content as a volume fraction using coring sleeves Gravimetric method 2 ISO 11272:1998, Soil quality Determination of dry bulk density 11 DIN ISO 16586:2012-05
