What is it? 
The TH2O is a new way to measure volumetric soil moisture content. It combines ease of use and accuracy with low cost, to give growers, land managers and engineers immediate precise soil moisture data. The probe is reliable even in saline soils and its compact size means minimal substrate disturbance.

How does it work? 
The sensor sends a microwave signal and analyzes a reflected signal to measure the dieletric constant (theta) of the soil.  The dielectric reading is then converted to volumetric water content (±1% accuracy).  The battery-powered hand held readout provides instantaneous readings for mineral or organic soils.

How do you use it? 
The TH2O probe is inserted into the soil and when the readout button is pushed the LCD shows the soil water content as a decimal value.

You may also install access tubes and take soil moisture reading from deep within the soil profile.

Customer Feedback

"We have had the TH2O for about three years, and bought another one this year. We are using the TH2O to watch putting surfaces, especially during summer, to track dry spots and irrigate to avoid drought stress."
- Todd Towery, Pinnacle Country Club

“It has worked very well for us, especially in predicting localized dry spots. It is one of the best tools that we have purchased in a long time. The TH2O takes the guess work out of irrigating.”
- Donald Altman, Forest Hills Country Club

“We have four TH2O 's, one for each of our reps. They are working well to demonstrate the effectiveness of turf surfactants to golf courses, and the customers that bought them, love them."
– Gary Rehm, Metro Turf Specialists


  • Sealed, waterproof probe, factory calibrated
  • Unaffected by salinity or temperature
  • Inserts with minimal disturbance - (4) 1/8” prongs
  • Operates in the range of 0-60% water content
  • Displays in volumetric water content and deficit
  • Stores up to 1100 time-stamped readings, accessed by PC
  • Readings include sample number, plot identification number, and a sensor number
Accuracy ±0.01 m3.m-3
Power Input 5 to 14 V, 18 mA for 1 s
Rod Dimensions 2.375" (60 mm),
Overall length 8" including pins
Extensions Choice of 50 cm or 100 cm (may be joined) For convenient walking about with probes. Fits into 2 in ID access tubes to deeper vadose zone.
Patents EUR 963703190.1, GB 9609372.9 USA 08\706675 Pend.
Display 16 x 2 character LCD
Soil moisture ranges zero to saturation. 0-1V on voltage range
Battery life Typically: 6500 readings for ThetaProbe type ML2x: 4500 readings fore Profile Probe type PR2/6
Size/Weight 150 x 80 40 mm, 450g
Battery 9 V Alkaline Cell (PP3)