INTEGRATOR GUIDE
TEROS 21 SOIL WATER POTENTIAL SENSOR
18204-00
11.10.2017
APPLICATIONS
• Deficit irrigation monitoring and control
• Water potential monitoring in the vadose zone
• Crop stress
• Waste water drainage studies
• Plant water availability
• SDI-12 implementation
ADVANTAGES
• Three-wire sensor interface: power, ground, and data
• Digital sensor communicates multiple measurements over a
serial interface
• Robust thermistor for accurate temperature measurements
• Low-input voltage requirements
• Low-power design supports battery-operated data loggers
• Robust epoxy encapsulation resists corrosive environments
• Supports SDI-12 or DDI serial communications protocols
• Modern design optimized for low-cost sensing
• Does not require a skilled operator
• Can measure drier systems where tensiometer cavitation
is a concern
• Needs no user maintenance
SENSOR DESCRIPTION
The TEROS 21 Soil Water Potential Sensor measures a wide range of soil water potentials without user
maintenance. This dielectric water potential sensor can be packed into a hole, plugged into a data logger, and
left to log water potential data. While the TEROS 21 sensor does not have the accuracy of tensiometers, its
extended range makes this sensor ideal for measuring the water potential in natural systems or other drier
systems where cavitation of tensiometers is a concern. The added temperature measurements can be used to
determine approximate soil water potential in frozen soils.
Figure 1 TEROS 21 sensor
PURPOSE OF THIS GUIDE
METER provides the information in this integrator guide to help TEROS 21 Soil Water Potential Sensor
customers establish communication between these sensors and their data acquisition equipment or field
data loggers. Customers using data loggers that support SDI-12 sensor communications should consult the
data logger user manual. METER sensors are fully integrated into the METER system of plug-and-play sensors,
cellular-enabled data loggers, and data analysis software.
COMPATIBLE FIRMWARE VERSIONS
This guide is compatible with firmware versions 3.89 or newer.
METER Group, Inc. USA
2365 NE Hopkins Court, Pullman, WA 99163
T
+1.509.332.2756
F
+1.509.332.5158
E
info@metergroup.com
W
metergroup.com
