In some cases, when the use of a heavy drilling rig is not possible due to its dimensions or access restrictions, as well as when working on the outside of buildings and in basements, a manual drilling tool – the STIHL BT121 motor drill – is used. The manual motor drill is mostly used to make low-depth boreholes (3 – 6 m), but in sandy soils, it is sometimes possible to reach a depth of 10 m. With this drilling tool, only auger drilling in the diameter of 63 – 100 mm is possible, resulting in relatively low representativeness of the obtained soil samples.