Sample division from NEXOPART: The first step of your analysis begins here.

Your analysis only becomes meaningful through precise sample preparation. First of all, you always need a representative sample quantity. If you receive your materials in bags, boxes and other large containers, the quantity is usually far too large to check using sieving or dynamic image analysis. You should therefore take a cross-section of the entire material quantity as a basic sample and only then start dividing the sample. Samples are often taken directly from the current material flow during production. You should bear in mind that the different grain sizes of your material are never evenly distributed in the natural flow. Therefore, only a flow cross-section ensures that you obtain a representative distribution of the actual grain sizes.

The main problem with sample division is dividing the material as precisely as possible into subsamples of exactly the same size. If the size of the individual subsamples differs from one another, they may no longer be suitable for the analysis procedure, as they usually have exact specifications for the sample quantity. These are usually very small, often in the milligram range. It is no longer possible to divide samples in these quantities by hand. Deviations of between 6 and 10 percent can occur in the partial sample quantity. With a sample divider, on the other hand, deviations of a maximum of 3 percent can be expected. However, this proportion is still too large for some analysis methods and sample sizes. With rotary sample dividers, the partial quantities deviate from each other by a maximum of 0.5 percent.

The sample divider works in a similar way to a sieve. The material is placed in a tray with evenly spaced passages at the bottom. These passages are precisely standardized so that the same amount of material is always discharged into the collection containers below. This simple process requires no electricity and is very easy to operate. Sample dividers are often used in the food industry for fertilizers, seeds and coffee. It is also frequently used to separate building materials, chemicals and minerals. The rotary sample splitter is used for very fine substances. The principle is based on a carousel, which is divided into several chambers of equal size. The material is filled into a funnel and transported to the rotary sample divider via a vibrating chute. Here the material falls onto a rotating cone, which enables the material to be evenly distributed into the individual sample chambers. The rotation speed is sometimes very high in order to be able to separate the smallest material quantities of a few milligrams.

The recommended size of a sample divider depends on the size of your particles to be divided. The opening size of the divider should be 2.5 - 3 x the size of the largest particle in the sample.