Complete Moisture Characteristics in 3-5 Days

HYPROP is a modular lab instrument that generates a moisture characteristic curve and determines the unsaturated hydraulic conductivity of soil samples in standard 250 ml soil sampling rings. After setup, the system generates the moisture characteristic while running unattended.

Highly Accurate

Two precision mini-tensiometers measure water potential at different levels within the sample while the sample rests on a precision laboratory scale (2000 gram range; 0.01 gram resolution). As the sample dries, changes in water potential are correlated to changes in moisture content using the Wind/Schindler evaporation method.

Verified Results

Results are verified and values for dry range and saturation are calculated according to a selected model (i.e., van Genuchten/Mualem, Bimodal van Genuchten/Mualem, or Brooks and Corey.) Model parameters can be selected before, during, or after the measurement procedure.


HYPROP Vacuum Refilling System 

The HYPROP base and tensiometers are usually filled using syringes. It requires some practice to achieve good results. In fact, a skilled user can typically extend the range of the HYPROP significantly.


Better Results for Novice Users

Using the vacuum to fill the HYPROP gives the user the best HyProp performance without the learning curve. 

The optional HYPROP Refilling System takes much of the painstaking precision work out of filling and setting up the HYPROP. It consists of a set of adapters that attach the base and tensiometers to a vacuum pump. 


How It Works

On the day before beginning a test, fill the tensiometers and HYPROP base with degassed water, put the system under vacuum, and leave it overnight. In the morning, you're ready to connect everything and start running a moisture characteristic curve on a soil sample. 


The Refilling System

  • Saves 20 - 30 minutes set up time per HYPROP
  • Typically increases HYPROP range, especially for novice users
  • Is especially useful in filling multiple HYPROPS




New HYPROP Software

The new data evaluation software brings a multitude of significant improvements for the evaluation of the data you obtain from HYPROP evaporation experiment campaigns.

The software also allows the input of data from other water potential instruments such as the WP4C for fitting the soil moisture release curves.


  • Easy and flexible handling
  • Usage of intact standard sampling rings without perforation
  • Tensiometer shafts are installed into the sample from the bottom side
  • Low expenditure of time and costs
  • Suitable for mobile applications
  • High-quality results for the water retention curve especially in the range close to saturation
  • The hydraulic functions are consistently proved by numerous readings
  • T5x Tensiometers may measure beyond 250 kPa due to boiling retardation
  • The mathematical functions are profoundly adapted
  • Simultaneous measurement of water retention curve and hydraulic conductivity
  • Suitable for all soils (provided Tensiometers can be installed)
  • No special requirements for the ambient conditions. Only the evaporation conditions should remain more or less constant during a measurement
  • An existing scale with serial port can be connected to the system
  • Extendable to up to 20 assemblies for one scale


  • The measuring range is limited to the measuring range of the Tensiometers
  • Poor resolution of the hydraulic conductivity near saturation (particularly in sandy soils)

+20 hPa to -1200 hPa / -2500 hPa
ACCURACY 1.5 hPa (0 hPa to 800 hPa)
PA66GFK, h = 60 mm, 80 mm
MEASUREMENT RANGE 0 to 2.5 kg                               

Extra Sample Rings

250 mL Stainless Steel Sampling Ring for collecting additional samples for the Hyprop.  Includes 2 caps.

Hammering Holder for Sample Rings

For use in collecting intact soil cores to be used with the Hyprop.  Hamerring holder for 250 mL sampling rings, length 300 mm, handle with hand protection.   

HYPROP Balance

The balance is directly connected to the PC via an USB plug. This offers you the possibillity to run multiple balances and HYPROP-devices simultaniously. You profit from an outstanding gain of time if you need to analyze a multitude of soil samples. The great advantage of the balance is its unique long-time stable "tuning-fork-principle". This pinciple is excellent for the evaporation
measurements of HYPROP.

The HYPROP-measuring head is directly connected to the scale and offers a clearly defined attribution of balance and measuring head. The HYPROP-FIT software detects the balance and the measuring head autmatically and assigns weighing values to the tension. To reduce weighing errors due to the cable, the new balance cable is much thinner and more flexible

HYPROP Extension Kit

Use an extension kit to run more than one soil sample at once. Run up to 10 extensions on a single Hyprop.

HYPROP Vacuum Refilling System

The HYPROP-refilling unit makes the refilling process more reliable and easy. With this device HYPROP sensor units and HYPROP-tensiometer shafts are conveniently connected to vacuum supplied by an external vacuum pump.

Simply screw the HYPROP-tensiometer shafts to one of the 4 adapters, and remove them easily when they are entirely degassed and filled. 

- The station is extendable
- Easy connection of sensor unit and shafts
- Separate vacuum pump
- Robust set-up
- Storage beaker for each cup
- Unlimited extendibility

Request Support

Phone: 509-332-2756
Fax: 509-332-5158