PR2 Profile Probe - analogue version

Soil moisture content profiles down to 1mDual purpose – installed and portableUses access tubes for easy probe insertion and removalSDI-12 interface option availableNo other soil moisture probe system

  • Product Name:PR2 Profile Probe - analogue version
  • Item No.:PR2
  • Manufacturers:Delta-T
  • Country of Origin:England
  • Soil moisture content profiles down to 1m

  • Dual purpose – installed and portable

  • Uses access tubes for easy probe insertion and removal

  • SDI-12 interface option available

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 or DL6) 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 – the PR2/6 measures at 6 depths down to 100 cm.

Both analogue and SDI-12 interfaces are available for the PR2. 

  • Highly reliable field-proven instrument

  • 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

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

HH2 Meter

The HH2 is a versatile readout unit that provides an easy and convenient way to display and store readings from Profile Probes. With the HH2 and PR2 combination, a probe can be moved from access tube to access tube, enabling large amounts of soil moisture data to be collected at multiple sites.

Data Logging

Profile Probes are available with analogue or SDI-12 outputs.

For the analogue version, order PR2/4 or PR2/6.

For the SDI-12 interface version, order PR2/4-SDI-12 or PR2/6-SDI-12.

Please note that analogue and SDI‐12 probes cannot be mixed on the same cable system

Loggers for analogue Profile Probes

Delta-T offers a choice of two data suitable data loggers. Both have dedicated PR2 Profile Probe input channels and connectors:

The DL6 Data Logger can log one PR2/6 or one PR2/4 Profile Probe

The GP2 Data Logger can log up to two PR2/6s or three PR2/4s

Loggers for SDI-12 Profile Probes

The PR2 SDI‐12 is ideally matched to the SDI‐12 enabled GP2 Data Logger. Many SDI-12 Profile Probes can be connected to a single GP2 (actual number depends on cable length, power, and other considerations).


Measurement        Volumetric water content

Accuracy              ± 0.04 m3.m-3 (4%)

With soil-specific calibration

Soil moisture measurement range              Full accuracy over:

0 to 0.4 m3.m-3

Full range : 0 to 1.0 m3.m-3

Salinity range                           50 to 400 mS.m-1

Salinity errors included in calibration

Temperature range                       Full accuracy over: 0 to 40°C

Output                                                    (ANALOGUE) 0 to 1.0 V differential PR2/6: x6 outputs, PR2/4: x4

Power requirement        (ANALOGUE) 5.5-15 V,

      PR2/6: ~120 mA for 1s

      PR2/4: ~80 mA for 1s

      Minimum 7.5 V with 100 m cable

Sleep curren              t <2 mA at 12 V DC

Environmental                   IP67 (when installed in access tube)

Sample volume            -95% sensitivity within a cylinder of diameter 200mm

   Sample volume is weighted towards soil immediately surrounding the rods

Dimensions and weight        PR2/6: length 1350 mm

        PR2/4 length 750 mm

        Both: 25.4 mm diameter

        PR2/6: weight 1.2 kg

       PR2/4: weight 0.8 kg

Sensor calibrations               Individual sensors are interchangeable

Recalibration advised            every 3 years (depending on use)

Soil calibrations              Generalised Mineral and Organic soil calibrations are suppl ied