Introduction to Sensor
The TEROS 32 Soil Tensiometer is a high-precision, plug-and-play solution for measuring soil water potential in outdoor environments. It combines direct pore pressure measurement with an integrated temperature sensor, eliminating the need for calibration while delivering reliable and accurate data. With seamless compatibility with the ZL6 data logger and ZENTRA Cloud, users can access and share measurements in near-real time.
Specifications
Specifications
Measurement Specifications
| Parameter | Specification |
|---|---|
| Water Potential | Range: –85 to +50 kPa Resolution: 0.0012 kPa Accuracy: ±0.15 kPa |
| Temperature | Range: –30 to +60 °C Resolution: ±0.01 °C Accuracy: ±0.3 °C between –0 and +40 °C (±1 °C outside of this range) Note: When using a continuous power supply, the temperature value may be displayed approximately 0.1 °C higher than it actually is. Using a ZL6 or other switching power supply does not create this effect. |
Communication Specifications
| Parameter | Specification |
|---|---|
| Output | DDI serial and SDI-12 communications protocol • 3- or 4-wire cable version. • RS-485 4-wire cable version. Modbus RTU and tensioLINK serial communications protocol • 4-wire cable version. • RS-485 4-wire cable version. |
| Data Logger Compatibility | METER ZL6 and EM60 data loggers or any data acquisition system capable of 4.0- to 28.0-VDC power and serial interface with SDI-12 and/or RS-485 interface, Modbus RTU, or tensioLINK. |
Physical Specifications
| Parameter | Specification |
|---|---|
| Dimensions | Diameter: 2.5 cm (0.98 in) Length: 40.0 cm (15.75 in) 80.0 cm (31.50 in) 120.0 cm (47.24 in) |
| Materials | Ceramic: Al2O3, bubble point 1,500 kPa Shaft: PMMA Corpus: POM GF Refilling Tubes: Stainless steel IP Rating: IP67 |
| Installation Angle | 10° to 80° from horizontal (downward) –10° to –80° from horizontal (upward) |
| Operating Temperature Range | Minimum: –30 °C (0 °C for water-filled tensiometer) Typical: NA Maximum: 50 °C NOTE: TEROS 32 electronic components continue to work at –30 °C, but freezing conditions can damage the pressure transducer when water is present |
| Cable Length | 5 m (standard)75 m (maximum custom cable length) NOTE: Contact Customer Support if a nonstandard cable length is needed. |
| Cable Diameter | Stereo Plug 4.2 ±0.2 mm (0.16 ±0.01 in) with minimum jacket of 0.8 mm (0.031 in) M12 Plug 5.5 ±0.2 mm (0.22 ±0.01 in) with minimum jacket of 1.0 mm (0.039 in) |
| Connector Size | 3.50 mm (diameter) 14.4 mm (diameter M12) |
| Connector Types | Stereo plug connector or stripped and tinned wires 4-pin M12 connector or stripped and tinned wires |
| Conductor Gauge | Stereo Plug 22-AWG / 24-AWG ground wire M12 Plug 22-AWG |
Electrical and Timing Characteristics
| Parameter | Specification |
|---|---|
| Supply Voltage Power to Ground | Minimum: 4.0 V Typical: 12.0 V Maximum: 28.0 V |
| Digital Input Voltage (Logic High) | Minimum: 1.6 V Typical: 3.3 V Maximum: 5.0 V |
| Digital Input Voltage (Logic Low) | Minimum: -0.3 V Typical: 0.0 V Maximum: 0.9 V |
| Digital Output Voltage (Logic High) | Minimum: NA Typical: 4.0 V Maximum: NA |
| Power Line Slew Rate | Minimum: 1.0 V/ms Typical: NA Maximum: NA |
| Current Drain (During Measurement) | Minimum: 18.0 mA Typical: 25.0 mA Maximum: 30.0 mA |
| Current Drain (While Asleep) | Minimum: .03 mA Typical: .05 mA Maximum: 0.9 mA |
| Power Up Time (DDI Serial) | Minimum: 125 ms Typical: 130 ms Maximum: 150 ms |
| Power Up Time (SDI-12) | Minimum: 125 ms Typical: 160 ms Maximum: 175 ms |
| Measurement Duration | Minimum: 60 ms Typical: 65 ms Maximum: 70 ms |
Other
| Parameter | Specification |
|---|---|
| BARO Module | When using the METER tensiometers TEROS 31 and TEROS 32 in combination with a non-METER data logger, a highly accurate barometric compensation is needed to get the most precise soil water potential measurement. The BARO Module can be used as a stand-alone sensor for measuring atmospheric pressure at a measuring site. It is also available with different connectors, so the BARO Module can be connected directly in between a tensiometer and a data logger. The BARO Module can also act as a digital/analog converter to connect a tensiometer with serial output to a data logger with analog input channels. The logger obtains a barometric compensated analog matric potential signal. The BARO Module can be used for varied logger communications: SDI-12, Modbus, tensioLINK, analog voltage signal. |
| Compliance | EM ISO/IEC 17050:2010 (CE Mark) 2014/30/EU and 2011/65/EU EN61326-1:2013 and EN55022/CISPR22 |
| Prop 65 warning | Prop 65 warning |
| GSA | View GSA details |
Features
Applications