METER HYPROP 2 – Soil Moisture Release Curves


The trouble with moisture release curves

Measuring soil water potential to create a moisture release curve has always been tricky. Even if you’re an expert at traditional methods, these measurements require a tremendous amount of work. Plus, you still face limitations—like a lack of data points—that affect the final result. Some methods take several months just to complete a partial curve. And if that wasn’t enough, there’s never been an easy way to measure the range of soil water potential for an entire curve. Until the HYPROP 2.

Simply accurate. Simply fast. Simply automated.

As soil scientists who have made hundreds of moisture release curves, we wanted an instrument that delivered greater accuracy. And we demanded an instrument that was automated. The HYPROP 2 takes only days vs. months to generate a soil water characteristic curve in the wet range, and it does this automatically.

Use the HYPROP 2 together with the WP4C (which measures the dry range), and you can create full, high-resolution moisture release curves across the entire range of soil moisture. Nothing else is capable of doing that—not at this level of detail.

On top of all that, we designed the HYPROP 2 to automatically determine unsaturated hydraulic conductivity on undisturbed soil samples placed inside a standard 250 mL sampling ring. Used in tandem with the KSAT, it can a generate a hydraulic conductivity curve for any soil type. The resulting instrument winds up saving you time, hassle and worry.

Unrivaled accuracy

When it comes to soil water potential, measurements don’t get any more accurate or precise. That’s because the HYPROP 2 produces more data points (over 100 data points in the 0 to -100 kPa range), higher resolution data, more detail, and better information in its moisture release curves—information that is missed when using the traditional pressure plates or hanging water column methods.

The HYPROP 2 uses two precision mini-tensiometers to measure water potential at different levels within a saturated soil sample while the sample rests on a laboratory balance. Over time, the sample dries, and the instrument measures the changing water potential and the changing sample weight simultaneously. It calculates the moisture content from the weight measurements and plots changes in water potential correlated to changes in moisture content.

Automated everything

The HYPROP 2 is a complex instrument, but it makes moisture release curves much simpler. While other methods require weeks of tedious drying and weighing, the HYPROP 2 can be set up to run automatically. Its software calculates values for dry range and saturation according to a selected model, and it even allows you to input data from other water potential instruments such as the WP4C to automatically fit the soil moisture release curves.

The faster, the better

After setup, the HYPROP 2 is capable of generating a moisture characteristic curve and determining the unsaturated hydraulic conductivity of soil samples in only days versus months. To save you even more time, it can operate while being left unattended.

The expert on moisture release curves (so you don’t have to be)

The HYPROP 2 generates the best data on the wet end of the soil water characteristic curve, with more details than any instrument on the market. Plus, you can combine the HYPROP 2 with any LABROS instrument for a complete soil analysis—the PARIO for soil particle size analysis, the WP4Cfor a complete moisture release curve, or the KSAT for a hydraulic conductivity curve. The result? Powerful tools for understanding data and predicting a soil’s behavior over time.

Unparalleled accuracy. Automation. Far faster speeds. The HYPROP 2 meets the highest lab instrumentation standards, giving you results you can trust with far less work and hassle.


1.5 hPa (0 hPa to 820 hPa)


0.01 hPa

Measurement range for tensiometers

+20 hPa to -1200 hPa / -2500 hPa

Dimensions without sample ring

PA66GFK, h = 60 mm, 80 mm


RS485 tensioLINK

Hyprop Manual


Hyprop Fit Manual


K-SAT and Hyprop 2