Plant

For every inter-laboratory comparison program it is very important that all distributed portions are equal. For every sample that is divided into buckets with our bulk divider a homogeneity test is carried out. Ten sub-samples are collected from random buckets during the subdivision of the sample.

For every inter-laboratory comparison program it is very important that all distributed portions are equal. For every sample that is divided into buckets with our bulk divider a homogeneity test is carried out. Ten sub-samples are collected from random buckets during the subdivision of the sample. These sub-samples are analysed by Chemisch Biologisch Laboratorium Bodem. When the subdivision over buckets is proved to be acceptable, the material can be divided into smaller test portions. In this process, which uses our specially constructed sample divider the material is split into homogeneous test portions which can be sent to the participants. From every sample a homogeneity test is carried out at samples which are regularly distributed over the batch. The samples can only be distributed to the participants of our WEPAL-programs after acceptance of this homogeneity test.


Procedure
Because it is impossible to determine all parameters offered in the programs, we made a selected choice in parameters and methods for the homogeneity tests.

Criteria have been:
Robustness of the method
Critical parameters
Cost of analysis

The parameters chosen for the homogeneity tests are given in the next table.