Hand-operated equipment can be applied for soil research up to a depth of 5 to 10 meter. In this product information leaflet a number of gouge augers are described. Their mutual quality is that they are all fitted with an almost half cylindrical operational part with parallel cutting edges running vertically, justifying the name gouge auger. This operational part may vary in length as well as in diameter. The most suitable length depends on the penetration resistance, the substance of the soil and the required boring depth. The longer the operational part the more vulnerable the auger is to torsion. The selection of the most suitable diameter depends on the composition and the structure of the soil and on the purpose of the research. In general a smaller diameter is applied in soils with a fine and/or dense structure, by comparison to soils with a loose structure (for instance young swampy peat).
 
The set consists of three bi-partite gouge augers with different diameters. By first taking a sample with the gouge with the largest diameter and subsequently with gouges having smaller diameters cross- contamination among the samples is avoided. The gouge augers can be pushed into the soil, or hammered (with an impact absorbing hammer). Because of the short operational length and the diminishing diameters the set is very suitable for profile research (nitrate research) in soils with a somewhat higher penetration resistance.