eLibrary >
BS EN ISO 21187:2021 Milk. Quantitative determination of microbiological quality. Guidance for establishing and verifying a conversion relationship between results of an alternative method and anchor method results >
Expand All
TOC Search:
BS EN ISO 21187:2021 Milk. Quantitative determination of microbiological quality. Guidance for establishing and verifying a conversion relationship between results of an alternative method and anchor method results, 2021
- undefined
- European foreword
- Endorsement notice
- Foreword
- Introduction
- 1 Scope
- 2 Normative references
- 3 Terms and definitions
- 4 Principles
- 4.1 General
- 4.2 Guidance for applied methods and laboratories
- 4.3 Organizational set-up
- 5 Consideration of factors influencing the conversion relationship
- 5.1 General
- 5.2 Environmental factors
- 5.2.1 General
- 5.2.2 Animal species
- 5.2.3 Bulk milk storage conditions
- 5.2.4 Seasonal variations
- 5.2.5 Sampling and pre-treatment of the test samples
- 5.2.6 Test sample preservation
- 5.2.7 Milk production conditions
- 5.3 Analytical factors
- 5.3.1 Instrument make and model
- 5.3.2 Chemicals
- 5.3.3 High somatic cell counts
- 6 Test samples
- 6.1 Calculation of number of test samples
- 6.2 Range of test samples
- 6.3 Representativeness of samples
- 6.4 Pre-treatment of test samples
- 6.4.1 General
- 6.4.2 Preparation of sub-samples
- 6.4.3 Storage and transport of sub-samples
- 7 Analysis
- 8 Establishing a conversion relationship
- 8.1 General
- 8.2 Validity of results
- 8.3 Conversion relationship
- 8.4 Calculations
- 8.4.1 General
- 8.4.2 Removal of outliers
- 8.4.3 Conversion relationship
- 9 Verification of a conversion relationship
- 9.1 Frequency of verification
- 9.2 Calculation
- 10 Test report
- Annex A (informative) Number of test samples for linear regression
- Annex B (informative) Example identification of outliers and calculation of conversion relationship
- Annex C (informative) Example — Calculation of significance (verification of conversion relationship)
- Bibliography [Go to Page]