Soil Sensor (Soil Suction)

Item name: Soil Sensor (Soil Suction or soil potential sensor)

Catalogue number: PUTD-TEROS 21

Device Description:

Soil environmental data monitoring is mainly suitable for agricultural cultivation in fields and greenhouses, suitable for soil, Long-term on-line monitoring of soil, especially through monitoring soil conditions, provides data support for planting, irrigation and management, and provides empirical data for better quality crop cultivation. This device tests the soil suction (potential) and temperature.

This sensor will work with PUTD IOT Technology’s Smart Agriculture Device to form site test appliance. By uploading data through wireless network, this combination will be further working with our cloud base IOT software platform(PUTD DSS) to provide the data view of soil suction (or soil potential) and temperature data.



Smart Agriculture Device


This is the hardware platform which at one end interfaces with variety of industrial sensors for agriculture (Soil Sensor this time) to collect field data and at the other end adopting one of radio connectivity systems to exchange the information with application software resides in data centre. (details)

Smart IOT device.png

Sensor description:

The TEROS 21 water potential sensor is incredibly easy to use. It requires no maintenance, and is accurate enough for most applications. In fact, the TEROS 21 provides an even more accurate soil moisture picture than measuring water content alone. A water content sensor only shows the percentage of water in the soil, but add a TEROS 21, and you’ll know if that water is available to plants and where it will move. Plus, unlike water content, matric potential isn’t dependent on soil type, so you can compare moisture between different sites. Not only that, the TEROS 21 is surprisingly affordable, especially when you consider it measures across a wide range, including dry values.

TEROS 21 maybe more accurate than the sensors by others. That’s because each sensor is calibrated. A chamber system that allows the TEROS 21 matric potential sensor to come to a fixed water potential. Sensors are put in silica flour, and by controlling the water potential, calibration points are set from -10 kPa to -80 kPa. The result: a long-term monitoring solution you can finally trust.

Ease of use isn’t something you normally associate with water potential measurement devices. Until now. That’s because TEROS 21 is plug and play in a number of ways.  First, once it’s in the ground, the durable epoxy coating ensures long-lasting usage. Second, no maintenance is involved. That means no refilling. And no worrying about frozen conditions. TEROS 21 is from METER which is one of industrial leading companies in world in soil environmental test. 



  • Easy to use

  • Improved accuracy comes from the six-point factory calibration

  • Tough, long-lasting body

  • No recalibration

  • Low salt sensitivity

  • Affordability

  • Excellent range (sensitivity from -9 kPa all the way to air dry [-100,000 kPa])

  • Onboard temperature measurement

  • Plug and play capability



  • Irrigation

    • Unlike water content, matric potential isn’t dependent on soil type, so you can compare moisture between different sites. it tells how easy it is for plant to extract water from soil.  By measuring this data, we can easyly make decision for irrigation without relative complex consideration of the variety of soil types 

    • Can work together with our multiple soil water content and  soil EC sensors to form more comprehensive data analysis tools to give the whole pictures of the farm land soil  

  • Pest and disease management

    • Beside soil water potential/suction which can be used as data supported irrigation, the associate soil temperature and 3rd party weather condition data may work together to forecast the pest and disease  ​