Dry soil samples which have hardened and clumped because of transport and storage, are milled, loosened, evenly screened and separated from coarse impurities in one operation by the screening machine. The soil sample is poured through a hopper into the working cylinder and milled and screened by the impact roller which rotates slowly over the screen on the working shaft. The size of the working gap can be changed by raising or lowering the fork lever to adjust the quality of the soil sample (loamy
or sandy).

The soil sample is milled evenly but not pulverised.