Tensiomark
Measures soil water tension from pF 0 up to pF 7 (1 up to 10,000,000 hPa); maintenance-free and frost resistant
Tensiomarks measure a special aspect of soil moisture, the soil matric potential. The matric potential (synonyms: pressure head, tension, or water potential) is an expression for the binding forces of water to the soil matrix and indicates the energy acting on the soil water and keeping it against the force of gravity inside the soil matrix. Because of adsorption and capillary forces the soil causes a water tension on the soil water. This matric potential is the highest at low water contents and decreases with increasing water content.
Key Features:
- Sensor covers complete measuring range (pF 0-7; 1-10.000.000 hPa)
- Maintenance-free and frost resistant
- Unlimited measuring range (no measurement gaps in summer due to dehydration)
- Fast response to moisture changes
- Measurement of soil temperature (only in SDI-12-mode)
- Depending on application different calibration classes are available (see technical data)
The relation between matric potential and water content is shown in Fig. 1 for three different soil textures:
| Measuring principle | Heat Capacity |
| Ranges | pF 0~pF 7,0 ≙ 1~10.000.000 hPa -40~+80 °C |
| Resolution | 0.01 pF, 0,1 °C |
| Accuracy | ca. +/- 30 hPa & 5 % FS = 0,35 pF Note: In general, best results will be produced with sensing cycles of 15 minutes because 15 minutes cycles are used in the calibration process |
| Shortest Sensing Cycle | 15 min |
| Waiting time | 15-20 sec (Duty cycle of the data logger before measurement) |
| Output signal | digital (SDI-12), optional analog |
| SDI-12-Signal | pF-Wert 0~7, Temp. in °C |
| Analog signal | -40°~60°C – Sensors can be used at higher temperatures under some conditions. Contact us for more details. Water potential measurements will not be accurate below 0°C. |
| Power supply | 7~14 V DC (12 V recommended) |
| Dimensions | L = 125 mm, D = 20 mm |
| Cable | Standard length: 5 m. Min. bending radius: 90 mm Sheath: PUR, UV-resistant, temperature range –30~+95 °C |
| Sensor Body | Stainless steel |
| Sensor Head | Ceramic |
Dorau et al. (2020): Climate change and redoximorphosis in a soil with stagnic properties; Catena 190:104528.