NEN EN ISO 20483 : 2013

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents
6 Apparatus
7 Sampling
8 Preparation of test sample
9 Determination of the moisture content
10 Procedure
   10.1 General
   10.2 Test portion
   10.3 Determination
   10.4 Blank test
   10.5 Test with reference material (Check test)
11 Expression of results
   11.1 Nitrogen content
   11.2 Crude protein content
12 Precision
   12.1 Interlaboratory test
   12.2 Repeatability
   12.3 Reproducibility
   12.4 Critical difference
13 Test report
Annex A (informative) Results of interlaboratory tests
Annex B (informative) Critical difference and practical
                      application of the repeatability and
                      reproducibility limits to different
                      protein contents
Annex C (informative) Factors for converting nitrogen content
                      to protein content
Bibliography

Defines a method for the determination of the nitrogen content of cereals, pulses and derived products, according to the Kjeldahl method, and a method for calculating the crude protein content.