EN 12945:2002

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Liming materials - Determination of neutralizing value - Titrimetric methods7LWULPHWULMVNHPHWRGHAmendements minéraux basiques - Détermination de la valeur neutralisation - Méthodes par titrimétrieCalcium-/Magnesium-Bodenverbesserungsmittel - Bestimmung des Neutralisationswertes - Titrimetrische VerfahrenTa slovenski standard je istoveten z:EN 12945:2002SIST EN 12945:2003en65.080ICS:SLOVENSKI
STANDARDSIST EN 12945:200301-oktober-2003







EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12945May 2002ICS 65.080English versionLiming materials - Determination of neutralizing value -Titrimetric methodsAmendements minéraux basiques - Détermination de lavaleur neutralisante - Méthodes par titrimétrieCalcium-/Magnesium-Bodenverbesserungsmittel -Bestimmung des Neutralisationswertes - TitrimetrischeVerfahrenThis European Standard was approved by CEN on 6 March 2002.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the 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 by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2002 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12945:2002 E



EN 12945:2002 (E)2ContentspageForeword.3Introduction.41Scope.42Normative references.43Terms and definitions.44Principle.45Reagents.56Apparatus.57Sampling.58Procedure.69Expression of results.710Precision.811Test report.8Annex A (informative)
Results of an interlaboratory trial to determine the neutralizing value.9Bibliography.10



EN 12945:2002 (E)3ForewordThis document EN 12945:2002 has been prepared by Technical Committee CEN/TC 260 "Fertilizers and limingmaterials", the secretariat of which is held by DIN.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by November 2002, and conflicting national standards shall be withdrawn at the latestby November 2002.Annex A is informative.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,Sweden, Switzerland and the United Kingdom.



EN 12945:2002 (E)4IntroductionTwo different procedures are described (method A and method B) because the titration to pH 7,0 is not applicableto silicate liming materials due to the precipitation of compounds at this pH value.In method B the turning point at pH 4,8 on the titration curve is taken as the end-point of the titration. Forcarbonaceous liming materials the difference in the consumption of sodium hydroxide solution for back titrationbetween the titration end-points of pH 4,8 and pH 7,0 is negligible.1 ScopeThis European Standard specifies two methods for the determination of the neutralizing value (NV) of limingmaterials.Method A is applicable to liming materials except silicate liming materials and liming materials with more than 3 %P2O5.Method B is applicable to all liming materials except those with more than 3 % P2O5.NOTEThe methods described in ISO 6598 and ISO 7497 can be used for the determination of P2O5 content.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN 1482, Sampling of solid fertilizers and liming materials.EN 12944-3, Fertilizers and liming materials — Vocabulary — Part 3: Terms relating to liming materials.EN ISO 3696, Water for analytical laboratory use — Specification and test methods (ISO 3696:1987).ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth.3 Terms and definitionsFor the purposes of this European Standard, the terms and definitions given in EN 12944-3 apply.4 PrincipleDissolution of the sample in a specified quantity of hydrochloric acid standard solution. Determination of the excessacid by back titration with a sodium hydroxide standard solution.



EN 12945:2002 (E)55 Reagents5.1 GeneralDuring the analysis, unless otherwise stated, use only reagents of recognized analytical grade and waterconfirming to grade 3 in accordance with EN ISO 3696.NOTECommercially available solutions can be used.5.2 Hydrochloric acid standard solution, c(HCl) = 0,5 mol/lDetermine the exact concentration of the solution by titration with sodium hydroxide standard solution (5.3) usingphenolphthalein solution (5.4) as indicator. Apply the appropriate correction factor in the calculation of the results(see clause 9).5.3 Sodium hydroxide standard solution, c(NaOH) = 0,25 mol/lDetermine the exact concentration of the standard solution by titration ag
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