The Soil temperature and volumetric water content sensor probe (Decagon 5TM) sensor can measure volumetric
water content and temperature of soil. The sensor uses an oscillator running at 70 MHz to measure the dielectric
permittivity of soil to determine the water content (VWC). A thermistor in thermal contact with the sensor prongs
provides the soil temperature.

Specifications
General specifications
•• Operating temperature: -40 to 60 ºC
•• Dielectric measurement frequency: 70 MHz
•• Measurement time: 150 ms
•• Dimensions: 10 cm x 3.2 cm x 0.7 cm
•• Prong length: 5.2 cm
•• Cable length: 5 m
 

Volumetric water content
•• Range: Apparent dielectric permittivity (εa): 1 (air) to 80 (water)
•• Resolution:
-- 0.1 εa (unitless) from 1 to 20,
-- < 0.75 εa (unitless) from 20 to 80
-- 0.0008 m3/ m3 (0.08% VWC) from 0 to 50% VWC
•• Accuracy: εa : ±1 εa (unitless) from 1 to 40 (soil range), ±15% from 40 to 80 (VWC)

Temperature
•• Range: −40 to 60 ºC
•• Resolution: 0.1 ºC
•• Accuracy: ±1 ºC