The resistance to penetration is a means of determining the ground load-bearing capacity, and the ease with which roots will grow through the ground (important when agricultural, rural- and civil engineering techniques are involved). The resistance to penetration is a mechanical characteristic that, given a certain texture, depends on changing parameters such as degree of humidity, density and the strength of the connection between mineral particles. Measuring the resistance to penetration of the soil in a great number of measurements is best executed applying an electronic penetrometer together with a datalogger, allowing for immediate storage and processing of the data in the datalogger. To this purpose Eijkelkamp Soil & Water developed the penetrologger: An electronic penetrometer with a built-in datalogger for storage and processing of a great number of measuring data (1500 measurements).
The penetrologger is a versatile instrument for in situ measurement of the resistance to penetration of the soil. 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 depth reference plate is also used to reflect the signals which are used to control the penetration speed. The measured resistance to penetration and the GPS coordinates are stored in the internal logger of the penetrologger. Depending on the application and the expected resistance to penetration, various cones can be connected to the probing rods. Optional is the possibility of soil moisture measurement with an external soil moisture sensor.
The penetrologger can be applied in the agricultural- as well as in the civil engineering sector: