Soil Moisture Sensor SM150T

SM150T Soil Moisture Sensor


The SM150T’s advanced patented electronics and tough build produce a highly reliable soil moisture sensor with exceptional salinity and temperature stability. The SM150T is engineered to withstand long term burial – the sensor, connectors and cable are all environmentally protected to IP68. It offers moisture accuracy of ± 3% (after soil specific calibration) and the built in temperature sensor achieves ± 0.5°C.


・Dependable ±0.03m3/m3 (± 3% F.S) soil moisture accuracy

・ADR method that is not affected by temperature and salinity (nutrient) fluctuations

・Applicable to other applications such as manual spot measurement and fixed point measurement with logger

・Suitable for -20 to +60°C environments (for research on irrigation, greening, hydrology, and global warming countermeasures)

・DC input range 5~14VDC for driving sensors. Output range 0~1.0VDC

・All products have been calibrated, so there is no individual difference when purchasing multiple products within the accuracy guarantee.

・Built-in thermistor temperature sensor


The SM150 Soil Moisture Kit provides an affordable and easy-to-use tool for obtaining reliable moisture measurements with minimal soil or substrate disturbance.

The kit comprises an SM150T* Soil Moisture Sensor, a dedicated HH150 Moisture Meter and a carry case. The cable and connector are watertight – an essential requirement for potentially wet environments.

The HH150 Meter displays volumetric water content (% volume). Please note that although the SM150T Sensor has a built-in temperature sensor, the HH150 Moisture Meter does not measure or display temperature

Soil Moisture Soil moisture+Temperature
SM150KIT ×
SM150T + HH2 ×
HH150: SM150 KIT 付属品 Handy Logger HH2
The HH150 is a display unit for direct reading only and data cannot be saved to a PC, etc. It is easy to operate and can be used by anyone. It is recommended for measurement while carrying. Some people may find it inconvenient just to display it as a KIT accessory HH150.For those who want to save data while carrying it around, we recommend combining it with the Handy Logger HH2.

Simultaneous measurement of soil moisture and soil temperature at multiple points

Some customers may want to simultaneously measure soil moisture and soil temperature with the SM150T. For those people, we recommend multi-channel data loggers.

Comparison table
Data Logger Soil Moisture+Soil Temperature Only Soil Moisture
GP1 Maximum 2 SM150T sensors Maximum 2 SM150T sensors
GP2 Maximum 6 SM150T sensors Maximum 12 SM150T sensors
MIJ-01 Maximum 8 SM150T sensors Maximum 16 SM150T sensors
MIJ-12 Only Soil Moisture Maximum 1 SM150T sensor

8 SM150T sensors connected to MIJ-01: The wiring is neatly organized.

Details of data loggers (Click the photo for details of each logger)






Power requirement DC5~14V(18mA) 
Output DC0〜1V(0〜0.6m3/m3)Output 0V in air.
Outputs more than 1V in fresh water.
*100% fresh water is a different condition than 100% soil VWC.
Sensor calibrations Individual sensors are interchangeable
Calibration coefficient

θ:volumetric water content m3/m3、VWC%=m3/m3×100、V:Volt、√ε:dielectric constant

Mineral Soil:

Organic Soil:

Dielectric constant:
√ε=1+14.4396V−31.2587V^2 +49.0575V^3 −36.5575V^4 +10.7117V^5

Response speed 0.1sec
Temperature Range Operation temperature range: -20~+60℃
Environmental IP68
Cable (optional) 5m cable
Extension cable (Maximum extension is 100m)
For SM150KIT 90 cm long cable is included
Accuracy ±3%(at0~60%、0〜60℃)
Salinity range ±5%(at0~60%、10〜1000mS/m) 
Size/ weight
Overall: 143 x 40 mm diameter
Rods: 51 mm x 2.5 mm diameter
Weight: 0.1 kg (exc. cable)


Brown/PWR 0V (GND),
White/PWR+ (Preheat)

SM150T Size

Burial possible

How to set SM150T

Related product

High Precision Thermometer ±0.05 MIJ-NLTP

・High sensitivity -0.1939℃/mV

・Fast response t63.2=2.6 seconds at Static Water

・Accuracy ±0.05℃ that exceeds Pt100 Class  AA standard

・Low power consumption 27.6μW(Overall, Max)