Soil moisture - Frequency domain (SMT100)

Parameter to be measured:

Soil moisture, permittivity, soil temperature

Method:

combination of Frequency Domain Reflectometry and Time domain Reflectometry

Equipment:

• SMT-100-sensor (TRUEBNER Instruments) with customizable cable length

Advantages:

• "quasi-TDR" method supposedly yields better results in clay soils
• Low cost
• Easy to install
• compatible with many loggers (RS485, SDI-12 or analogue protocol)

Disadvantages:

• Soil specific calibration required for highest accuracy

What to watch out for:

• Good contact between probe and medium required
• coarse soil may require extra tool for penetrating the soil before installing the sensor

Links

Manufacturer:

• Truebner

Projects that used the above equipment:

• TERENO
• PYROPHOB