The penetrometer basically consists of a measuring device, a probing rod and a probing cone. The instrument is pressed into the ground at a right angle by applying pressure to both handles. Jerky pressing results in non-representative readings that are overestimated for specific soils. The resistance measured by the probe cone is shown by the black pointer of the manometer. The maximum resistance recorded during the measurement is shown by the red pointer. The penetration resistance of the soil (kPa/cm²) can be determined by dividing the displayed value by the surface area of the probe cone. The value to be expected for the penetration resistance determines the surface of the probe cone to be used. For higher values, a smaller cone is used. 

General principle: the larger the probing cone, the more precisely the penetration resistance can be determined.

Penetrometers are used to determine the penetration resistance (load bearing capacity) of the soil. The Eijkelkamp penetrometer can be supplied in two different sets:

• Set for a depth of up to one metre
• Set for a depth of 3 metres

Applications

Due to its depth range, the device can be used for the following tasks:

• general soil analysis
• simple foundation notes
• investigations of the artificial compaction of the soil
• investigations of the growth conditions for plants to be expected
• determination of compacted horizons