A.C. van Herwaarden
Bemonsteringsinstallaties in de praktijk.
Report 99.3.TT.5152, Transport Engineering and Logistics.
The reason for sampling is to collect a manageable mass of material, called
the sample, that is representative of the total mass of material. The sample
is used for analysis of several quality-related parameters of the material.
Since the sample is only a part of the total mass of material, the exact
values of these parameters will not be known but it can be assumed that the
parameter values of the sample approximate the exact values of the total
mass with a certain accuracy.
Large scale sampling nowadays is often done by using mechanical sampling
installations. This report describes the general practice of sampling and
the most important aspects of automatic sampling equipment. The sampling
installations are generally designed according to industrial standards that
prescribe every step of the sampling process. The mechanical sampling
installation used by the EMO, also described in this report, is a good
example of automated sampling in the bulkhandling industry. Sampling is
also done in the raw materials for food industry. Sampling at the Suikerunie
in Dinteloord for instance, is also almost fully automated. The design of this
sampling process is the result of many experiments and years of experience.
Usually the design of sampling equipment is a compromise between the
desired accuracy and the costs involved. To test a sampling installation, a
bias test has to be done. When bias is found, tracking down the cause of
the bias can be a time-consuming process and result in higher costs.
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