The term "aggregate sample" (also known as a composite or mixed sample) refers to a sample consisting of several incremental samples taken from different parts of a bulk pile or stream and then mixed together. The aggregate sample is used to obtain a representative sample of the entire material.
Here are some aspects that are taken into account when creating a bulk sample:
- Representativeness: Since bulk material can often be heterogeneous, an aggregate sample is taken to ensure that the sample represents the entirety of the material. By mixing individual samples from different parts of the material, an average composition is obtained.
- Sampling plan: A well-planned sampling plan is crucial to determine where, when, and how the incremental samples will be taken. The number of incremental samples, their size and the method of their collection should be carefully selected in order to obtain a representative aggregate sample.
- Mixing: The incremental samples are collected in a container and thoroughly mixed to produce a homogeneous aggregate sample. This step must be carried out carefully to ensure that the aggregate sample represents the entire bulk material evenly.
- Analysis: The aggregate sample is then analyzed in the laboratory. Because it is the mixed composition of several incremental samples, it provides a better picture of the overall quality or composition of the bulk material than a single sample.
- Contamination control: Since the aggregate sample consists of several incremental samples, care must be taken to ensure that the collection, storage and mixing of the samples is carried out in a manner that prevents contamination or alteration of the sample.
Aggregate samples are used in various industries, including food, feed, mining, chemicals, and more. They are an important tool to enable accurate and reliable analysis of a bulk material, which can vary in composition.