Technical Specifications

Measurement Specifications

Water Potential

Range: –85 to +50 kPa (up to –150 kPa during boiling retardation)

Resolution: ±0.0012 kPa

Accuracy: ±0.15 kPa

Temperature

Range: –30 to +60 °C

Resolution: ±0.01 °C

Accuracy: ±0.50 °C

NOTE: If the sensor unit is not buried, measured temperature may diverge from soil temperature.

Communication Specifications

Output

DDI serial
SDI-12 communication protocol
TensioLINK^TM communication protocol
Modbus^TM RTU communication protocol

Data Logger Compatibility

METER ZL6 and EM60 data loggers or any data acquisition system capable of 3.6- to 28.0-VDC excitation and SDI-12, Modbus RTU, or TensioLINK communication.

Physical Specifications

Dimensions

Width: 23.5 mm (0.93 in)

Height: 49.0 mm (1.93 in)

Depth: 17.5 mm (0.69 in)

Tensiometer Shaft Diameter

5 mm (0.19 in)

Tensiometer Shaft Length

2, 5, 7, 10, 15, or 20 cm

Materials

Ceramic: Al₂O₃, bubble point 500 kPa

Shaft: PMMA

Sensor Unit: PMMA and TPE

Operating Temperature Range

Minimum: 0.00 °C

Maximum: 50.00 °C

Cable Length

1.5 m

Cable Diameter

3.0 mm (0.12 in)

Connector Types

4-pin stereo plug connector

Stereo Plug Connector Diameter

3.5 mm

Conductor Gauge

31 AWG drain wire

Electrical and Timing Characteristics

Supply Voltage (VCC to GND)

Minimum: 3.6 VDC

Typical: 12.0 VDC

Maximum: 28.0 VDC

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)

Typical: 3.6 V

Power Line Slew Rate

Minimum: 1.0 V/ms

Current Drain (During Measurement)

Minimum: 18.0 mA

Typical: 25.0 mA

Maximum: 30.0 mA

Current Drain (While Asleep)

Minimum: 0.03 mA

Typical: 0.05 mA

Maximum: 0.90 mA

Power Up Time (DDI Serial)

Minimum: 125 ms

Typical: 130 ms

Maximum: 150 ms

Power Up Time (SDI-12)

Minimum: 125 ms

Typical: 130 ms

Maximum: 150 ms

Power Up Time (SDI-12, DDI Serial Disabled)

Minimum: 125 ms

Typical: 130 ms

Maximum: 150 ms

Measurement Duration

Minimum: 60 ms

Typical: 65 ms

Maximum: 70 ms

Other

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. 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)

GSA

View GSA details