SM150T Soil Moisture Sensor

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"We recently purchased fifteen SM150 units. They are working excellently and are proving to be very robust and resilient." Aaron Schmocker
Bern University of Applied Sciences
"We used the instrument for 4 days of intense field work at 15 conservation areas across the Greater Toronto area - more than 200 readings per day. The Sensor proved to be an invaluable asset to our research project. It is fast, light weight and very energy efficient." Nao Ito, Graduate Student
York University, Toronto

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  • 5-year-warranty   Stable and accurate (± 3%)
  •    Robust and buriable with 5 year warranty*
  •    Ideal for substrate monitoring
  •    Built-in temperature sensor

The new SM150T is an affordable soil moisture and temperature sensor that is ideal for system integrators

SM150 Sensor – a versatile sensor for growers and system integrators

The SM150T is the perfect sensor for a wide range of applications in horticulture and agriculture. It can be used in both soils and substrates and is buriable. In addition, the SM150T offers excellent salinity and temperature stability.

The SM150T is a reliable and cost-effective solution for system integrators, who appreciate its ease of installation and simple interface (0 – 1 V DC output).    

SM150 Kit – for instant readings

The SM150 Kit combines the SM150T Sensor with a handy readout meter, providing growers with a low cost, portable, and easy to use tool for obtaining instant accurate moisture measurements.  Find out more about the SM150 Kit.

NB: When used in portable mode the SM150T Sensor does not provide temperature indication. To record temperature the sensor must be fully buried and connected to a suitable data logger.

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Easy installation

The SM150T’s sharp pins minimise soil disturbance, preserving the original soil structure around the measurement rods, and making the probe easy to insert and install. For burial at depth the cylindrical shape facilitates installation in augered holes. Optional extension tubes assist with placement and removal (50 cm and 100 cm lengths, connectable).


Horticulture – The SM150T Sensor is available (see SM150 Kit) with substrate calibrations for perlite, coir, peat, and mineral wool, as well as soils – providing a simple, effective, rugged solution to checking the uniformity of growing conditions for many types of growing media.

Irrigation – Accuracy and ease of use make SM150T Soil Moisture Sensors well suited to irrigation applications. The SM150T’s compact size (143mm total length – rods 51mm long) allows it to be easily installed in plant pots or grow bags. Readings can be used to optimise irrigation scheduling, or the SM150T can be installed as part of an automatic irrigation system.

System integration – The SM150Ts accurate and stable measurement (± 3% for 0-70% VWC** range), simple 0-1 V output (moisture), and low power (18mA for 1 second) makes it the ideal sensor for system integrators.

Patented sensor electronics produce research-grade accuracy performance alongside exceptional salinity and temperature stability – an essential combination for critical control and irrigation decisions.

Industrial rated, UV resistant cable fitted with a waterproof IP68 connector allows the sensor to be buried indefinitely, whilst still permitting easy cable exchange or extension if necessary.

More information is available in the SM150T System Integrator Data Sheet.

Data logging

The SM150T is compatible with all Delta-T Devices Data Loggers and its 0 to 1 V DC output can be handled by most other types of data logger. Temperature measurement (10 K thermistor) requires burial of the probe.

Product history

The new SM150T replaces both the SM300 and SM150 Sensors, combining their strengths and offering great value.


* Extended 5 year warranty requires online registration.

**Volumetric water content


Accuracy ± 0.03 m3.m-3 (3%) volumetric water content (VWC)
± 0.5°C (0 to 40°C for temp sensor)
Soil moisture measurement range 0 to 1.0 m3.m-3 (100%)
but less accurate above 70% VWC
Salinity range 50 to 1000 mS.m-1
± 5% vol over 100 to 1000 mS.m-1 and 0-60% VWC
Temperature range Full accuracy over: 0 to 60°C
Output 0 to 1.0 V differential
Corresponding to 0 to ~0.6 m3.m-3
Power requirement 5-14 V, ~18 mA for 1s
Minimum 5 V with 100 m cable
Environmental IP68 with Delta-T supplied cables
Sample volume ~55 x 70 mm diameter
Sample volume is weighted towards soil immediately surrounding the rods
Dimensions and weight Overall: 143 x 40 mm diameter
Rods: 51 mm x 2.5 mm diameter
Weight: 0.1 kg (exc. cable)
Sensor calibrations Individual sensors are interchangeable
Recalibration advised every 3 years (depending on use)
Soil calibrations Generalised Mineral and Organic soil calibrations are supplied

Product Resources

Data Sheets



Regulatory Information