tensiometers for soil columns
The E-Test unique tensiometer, or capillary pressure laboratory probe, is the ideal solution for engineers and scientists for soil columns research. The LP/p is a small tensiometer, 3mm diameter and 15mm in length. The LP/p is easy to maintain and install inside of soil columns for continuous, matric potential measurements.
LP/p is a laboratory miniprobe designed for monitoring instantaneous profiles of soil water capillary pressure (matric potential, suction force) in soil columns or in undisturbed soil cores sampled with standard sampling equipment. LP/p is pushed into the soil core and fixed with a clamp nut. Several LP/p probes can be inserted through the wall of a soil column or a steel sampling cylinder, thus allowing for vertical scanning of the instantaneous water potential profiles. Such an array, when combined with similarly installed miniprobes for soil moisture (LP/ms probes), enables collecting a set of corresponding water content and matric potential data from drying or wetting front transition. From the collected data set, after further processing, one can obtain a complete set of the unsaturated water flow characteristics of the soil, that is: water retention (PF-curve), unsaturated water conductivity (k-function), differential water capacity and unsaturated water diffusivity.
features and specifications
- Operates with a TDR/MUX/mpts unit.
- Relative error: ±15%.
- Resolution: 1 mbar.
- Offset drift: ±20 mbar/month.
- Delay: 0 to 800 mbar in about 120 s, 800 to 0 mbar in about 3 s.
- Available custom cable lenghts.
- Up to eight LP/p probes can be connected to one TDR/MUX/mpts device at the same time with the use of BNC T-splitters.
- Pressure diaphragm: a ceramic cup 15 mm long with 3 mm in diameter.
- Air-entry pressure: about 900 mbar.
- Replaceable ceramic cup element.
- Pressure transducer: an integrated, fully active Wheatstone bridge with four piezo-resistive strain gauge resistors diffused into a silicon diaphragm.
- Available probe clamps for securing the probe in a sample cylinder.