No other soil moisture probe system enables you to monitor your soil water profiles with such ease and flexibility. Install an access tube into the soil, insert the PR2 Profile Probe and press the HH2 [Read] button to display an instantaneous reading, or connect the PR2 to a data logger (GP2, DL6 or DL2e) and leave the system to record soil moisture changes over time.

The PR2 soil moisture probe is built around patented sensing technology which provides unprecedented performance in all soil types, with minimal influence from either salinity or temperature. The PR2/4 model measures soil moisture at 4 depths down to 40 cm or the PR2/6 measures at 6 depths down to 100 cm.

The PR2 Profile Probe is available in two sizes to measure to a depth of 40 cm or 100 cm.

The PR2/4 has sensing elements at 10/20/30/40 cm

The PR2/6 has sensing elements at 10/20/30/40/60 and 100 cm


  • Highly reliable field-proven instrument
  • Soil moisture content profiles down to 1m
  • Soil moisture content – not just trends
  • Out of the box solution – supplied with calibrations for common soil types
  • Portable meter option for multi-site measurement
  • Dual purpose – installed and portable
  • Uses access tubes for easy probe insertion and removal
Model Types PR2/4 and PR2/6
Sensing Depths

PR2/6: 10, 20, 30, 40, 60, 100cm

PR2/4: 10, 20, 30, 40cm (nominal)


Volumetric soil moisture content V

(m³.mˉ³ or % volume)


Accuracy figures apply from 0 to 0.4 m³.mˉ³

Full range is from 0.0 to 1.0 m³.mˉ³


0.0 to 0.4 m³.mˉ³

0.0 to 0.4 m³.mˉ³


±0.04 m³.mˉ³, 0 to 40ºC

±0.06 m³.mˉ³, 0 to 40ºC


Typical, after calibration to a specific soil type

Typical, using the generalized soil calibrations in 'normal' soils

Salinity Errors Include in above accuracy figures (50 to 400 mS.mˉ¹, 0.5 to 4 dS.mˉ¹, pore water conductivity)
Soil Sampling Volume

Vertically: ~95% sensitivity within ±50mm of upper ring of each pair.

Horizontally: ~95% sensitivity within a cylinder of radius 100mm.

Environment 0 to 40ºC for full accuracy specification, -20 to +70ºC full operating range. IP67 rated when installed in access tube.
Response Time Full accuracy achieved within 1 second²
Power Requirement

Minimum: 5.5V DC with 2m cable, 7.5V with 100m.

Maximum: 15V DC, PR2/4 consumption: < 80mA, PR2/6 consumption: < 120mA

Outputs 4 (PR2/4) or 6 (PR2/6) analogue voltage outputs: 0 to 1.0V DC corresponding to 0 to 0.6 m³mˉ³ (mineral calibration).
Cable Standard and extension cables (see ordering information)
Construction 25.4mm polycarbonate with pairs of stainless steel rings.

PR2/4 length: 29" Weight: 1.3 lbs.

PR2/6 length: 53" Weight: 2 lbs.