# Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1996, Paragraph 7: EXPRESSION OF RESULTS


Original dry mass
7.1 Calculate the original dry mass (Md) of material, using the following formula.
Md=M×DM where:
M is the mass of the test portion taken for the sieving test.
DM is the percentage dry matter obtained in 6.
Sieve fraction
7.2 Calculate the percentage of material retained on each sieve, using the following formula:
Xn=Mn/Md×100 where:
Xn is the percentage by mass retained on sieve n.
Mn is the dry mass retained on sieve n.
Md is the dry mass of the test portion.
Report the percentages of material (100 − Xn) which will pass through each sieve.
Carry out two single tests on separate test portions prepared from the same original sample. Record the mean of the two individual results for each sieve as the result (corrected if necessary for the presence of lumps (4.1)).

---
Source: https://www.legislation.gov.uk/nisr/1996/513/schedule/2/part/II/chapter/9./paragraph/7 (the official version)
Page: https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-II/chapter-9./paragraph-7
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.