Stem water potential sensors (microtensiometer)
The FloraPulse microtensiometer is a novel yet proven MEMS sensor (Micro-Electro-Mechanical System) for the continuous measurement of the stem water potential in woody plants.
The nanoporous silicon membrane used in the sensor with a pore diameter of approx. 2 nanometers enables measurements of water potentials of down to -35 bar!
After a simple installation (approx. 20 to 30 minutes), in which the microchip tensiometer is embedded in the wood tissue of the plant, the sensor provides you with directly measured, continuous water potential data of the instrumented plant. The sensor thus replaces extremely time-consuming, expensive and not entirely safe (pressure bomb as high-pressure instrument) manual measurements on site using a pressure bomb..
Compared to determining water potential using pressure chamber measurements (the most proven manual method to date), microtensiometers often provide more precise and more comparable data quality, as they are not operator-dependent as is often the case with pressure bombs (i.e. different users receive different results).
The sensor is available with an analog differential or digital SDI-12 output signal and can be operated with appropriate loggers.
Being a low low-power sensor, it is ideally suited for battery-operated IoT applications.
We would be happy to advise you in this regard and can also supply you with the appropriate logger technology if required.
Advantages
- Continuous water potential data in real time
- Can remain installed in the same tree for over 1 year (limited in case frost may occur)
- Easy installation in < 30 minutes.
- Installation wind and rain proof, designed for measurements under field conditions
- No more laborious, time-consuming and dangerous pressure bomb measurements
- Extremely low power consumption, suitable for IoT application
- Compatible with many data loggers (analog sensor with differential sensor signal in mV, or digital SDI-12 output)
Limits
- At very low water potentials < -15 bar, cavitation can occur in the sensors
- Exposing the sensors to temperatures of < 0°C can lead to defects
Technical Data
Sensor model name | FloraPulse stem water potential sensor |
Scope of application | For continuous measurement of water potential in woody plants. |
Suitable for stem diameter | Recommended for stem diameters of > 5 cm |
Limitiation / special feature | Recommended for operation at temperatures 5 to 50°C. Temperatures < 0°C may damage the sensor. |
Measurement range | 0 to -35 bars |
Resolution | Theoretically infinite, depending on data logger used, e.g.: Campbell-Logger or Multi-Interface: < 0.1 bar |
Accuracy | better than +/- 5% of the reading |
Data logger requirements & sensor output signal | analog sensor:
SDI-12 sensor:
All Campbell loggers and our Multi-Interface meet the above requirements. |
Power supply | Vex (! regulated, low-noise !) 1 to 5 VDC, excitation duration max. 50 ms Power consumption is negligible. |
Operational conditions | Temperature: 5 to 50 ° C, humidity: 0 to 100% |
Size and weight | Diameter sensor 12 mm, weight 20 g (only sensor, without cable) |
Sensor cable length | analog sensor: 0.15 m + 5 m pluggable extension, extension to up to 60 m possible. |