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1、International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATlON.MEYHAPOHAR OPrAHM3AtblR llOCTAHAPT3AUHM*ORGANlSATlON INTERNATIONALE DE NORMALISATION Fertilizers - Determination of ammoniacal nitrogen content - Titrimetric method after distillation Engrais - Dosage de l azote ammoniacal - M V2
2、is the volume, in millilitres, of the standard volumetric sodium hydroxide solution (4.4) used for the determination; Va is the volume, in millilitres, of the standard volumetric sulphuric acid solution (4.5) used for the blank test (50,O ml); V4 is the volume, in millilitres, of the standard volume
3、tric sodium hydroxide solution (4.4) used for the blank test; m is the mass, in grams, of sample in the aliquot portion taken for the determination. NOTE - If the concentrations of the standard volumetric solutions used are not exactly as specified in the list of reagents, appropriate corrections sh
4、ould be made. 7.2 Precision The statistical information given below was obtained from analysis of 22 sets of results (two operations in each case, each operator carrying out two determinations) from laboratories in seven different countries. The difference between successive test results, obtained b
5、y the same operator with the same apparatus under constant operating conditions on identical test material should not, in the long run, in the normal and correct operation of the test method, exceed the value of 0,03 % (m/m) at a confidence level of 95 %. 7.2.2 Reproducibility The difference between
6、 two single and independent results, obtained by different operators working in different laboratories on identical test material should not, in the long run, in the nor- mal and correct operation of the test method, exceed the value of 0,09 % (m/m) at a confidence level of 95 %. 8 Test report The t
7、est report shall include the following particulars : a) the reference of the method used, i.e. IS0 5314; b) the results and the method of expression used; cl any unusual features noted during the determination; d) any operation not included in this international Stan- dard or regarded as optional. 3
8、 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 23:15:13 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 5314-1981 (E) Dimensions in millimetres Op
9、en-top cylindrical dropping funnel Znhoripal nwunnd inint Yr*.-.“. J.I- ,-.- or rubber bung 7 44 300 / / N +I E 11 c Round bottomed flask 1 Figure - Typical distillation apparatus 4 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 23:15:13 MDTNo reproduction or networking permitted without license from IHS -,-,-