The carrying capacity of the soil is simple to measure with the penetrologger. The penetrologger measures the resistance of the soil or the shallow subsurface and is a suitable instrument for use in civil engineering, soil science, agriculture, sports field maintenance and park and public garden management. For civil engineering purposes a high degree of resistance is generally desirable. This concerns the ability to determine the suitability for foundations for buildings and infrastructure projects. Conversely, for agricultural purposes an excessively high resistance can present problems. A high degree of compaction can impede root development and the oxygen supply to the roots. When the resistance is too low this can mean too little carrying capacity for cattle to walk round or for agricultural machinery to operate. Unified Soil Classification System The so-called Unified Soil Classification System (USCS) determines whether a vehicle carrying a load is able to drive across a certain piece of land. The classification is expressed in figures, one for the vehicle and one for the soil. The figure for the vehicle, the Vehicle Cone Index ( VCI ), has no dimension and is based on various factors, e.g. soil accessibility, soil pressure and the ratio between engine capacity and weight of the vehicle. The Cone Index (CI) represents the soil figure. This figure can be determined by means of a cone-penetrometer. A comparison of both indexes shows the suitability of the terrain for driving over. The penetrologger consists of: the penetrologger with force sensor, a bi-partite probing rod, a cone, the depth reference plate, a communication port and a GPS antenna. The cone is screwed on the probing rod, which is connected with a quick coupling to the force sensor on the penetrologger. Now the cone is pushed slowly and regularly into the soil. The depth reference plate, which is on the soil surface, reflects the signals of the ultrasonic sensor, which results in a very accurate depth measurement. The measured resistance to penetration and the GPS coordinates are stored in the internal logger of the penetrologger. Optional is the possibility of soil moisture measurement with an external soil moisture sensor (1 measurement per penetration). Characteristics new penetrologger: Display of Vehicle Cone Index Precise internal GPS -system Optional soil moisture measurement Larger storage capacity Inclusion of French and Spanish language functions Simplified operation New PC software New robust design Technical specifications: Operating temperature 0 - 50 °C Operating humidity IP 54 (splash water proof) Penetrologger weight 3.4 kg (7.5 lbs) (excl. rod, incl. battery) Overall carrying/shipping weight 15.5 kg (34 lbs) Dimensions for transport 58x29x25 cm (23x12x10 inch) Memory 1500 measurements Maximum penetration force 1000 N Force resolution 1 N Depth registration 80 cm Depth resolution 1 cm GPS accuracy < 2.5 CEP (Circular Error Probable) Soil moisture resolution 1%