# Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1996, Paragraph 8: EXPRESSION OF RESULTS


Method of calculation and formulae
8.1 If the quantities and the dilutions shown in the Table are used, the following formulae apply:
%K2Ointhefertiliser=(A-a)×f or
%Kinthefertiliser=(A-a)×f' where:
A = mass in grams of the precipitate from the sample
a = mass in grams of the precipitate from the blank
f and f' = factors — see Table.
With samples and dilutions which differ from those of the Table use the following formulae:
%K2O=(A-a)×F×D×100M
or
%K=(A-a)×F'×D×100M where:
F = conversion factor, KTPB into K2O = 0.1314
F' = conversion factor, KTPB into K = 0.109
D = dilution factor
M = mass in grams of the sample for analysis.
TABLE FOR METHOD 11
% of K2O in the fertiliser
% of K in the fertiliser
Sample for analysis (g)
Aliquot portion to be taken as a sample for precipitation (ml)
Conversion factor f % K2O g KTPB
Conversion factor f' % K g KTPB
1-5
0.8-4.2
20
50
13.14
10.91
5-10
4.2-8.3
10
50
26.28
21.81
10-20
8.3-16.6
10
25
52.56
43.62
20-50
16.6-41.5
10
10
131.40
109.10
more than 50
more than 41.5
5
10
262.80
218.10

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Source: https://www.legislation.gov.uk/nisr/1996/513/schedule/2/part/I/chapter/11./paragraph/8 (the official version)
Page: https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-I/chapter-11./paragraph-8
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.