Operating principle of the TEROS 21 soil water potential probe
The TEROS 21 soil water potential probe from METER Group measures within a wide measurement range (-9 to -100000 kPa).
In addition, the TEROS 21 probe includes a temperature sensor to complement the water potential measurements. This allows two different variables to be measured in the same probe.
The TEROS 21 probe is basically composed of a humidity sensor and a porous ceramic of which the humidity retention curve is known.
Once the TEROS 21 soil water potential probe is installed in the soil matrix, the potential is balanced inside and outside the ceramic.
The sensor then measures the moisture content of the ceramic and converts it to water potential using the moisture retention curve of the porous capsule.
Easy field installation to obtain quality data
One of the advantages of the TEROS 21 soil water potential probe is that its installation is quick and easy.
To do this, when the installation depth has been decided, you only have to mix a sample of soil and water to form a clay ball and place it around the porous ceramic.
In this way, good contact between the porous ceramic and the soil matrix is ensured.
The TEROS 21 water potential probe is robust and durable
The TEROS 21 soil water potential probe is a robust and durable probe, making it ideal to be installed in the field and monitor water potential over long periods of time.
| Technical specifications of the TEROS 21 probe |
| Precision: |
Potencial hídrico del suelo: * (10% + 2 kPa) de -9 a -100 kPa; |
| |
Temperatura del suelo:* 1 °C |
| Resolution: |
Potencial hídrico del suelo: 0,1 kPa |
| |
Temperatura del suelo: 0,1 °C |
| Measurement range: |
Potencial hídrico del suelo: -9 a -100,000 kPa Temperatura del suelo: -40 a 60 °C |
| Measurement speed: |
150 ms (milisegundos) |
| Feeding time: |
100 ms (D01), 150 ms (SDI-12) |
| Equilibrium time: |
10 min a 1 h dependiendo del potencial hídrico del suelo |
| Sensor type: |
Dominio de frecuencia con discos cerámicos calibrados, termistor. |
| Exit: |
DDI serie o Protocolo de comunicación S01-12 |
| Operating environment: |
-40 a 60 °C |
| Power: |
3,6 – 15 VDC, 0.03 mA inativo, 10 mA max. durante una medida de 150 ms |
| Wire: |
5 m de cable (estándar). Conector ‘estéreo» de 3.5 mm o cables de plomo pelados y estallados |
| Probe Dimensions: |
9,6 cm (I) x 3,5 cm (a) x 1,5cm (d) |
| Datalogger Compatibility: |
METER (series ZL6, EM50 / 60), ProCheck (rev 1.53+), Campbell Scientific. cualquier registrador de datos compatible con S01-12 |
| Warranty: |
Un año, piezas y mano de obra. |
Applications of soil water potential monitoring
- Monitoring of water potential in the unsaturated zone;
- Water stress;
- Wastewater drainage studies;
- Control and monitoring of irrigation programming and management in substrate crops;
- Aquifer recharge;
- Slope stability.
