METER T4 Tensiometer – Field Water Potential

The cause of tension in tensiometers

The problem with most tensiometers is that they don’t stand up to year after year of harsh weather conditions like frost. Plus, you’re constantly pulling the tensiometer up to check the water level, which can be especially frustrating during long-term studies.

The search is over

Introducing the T4 Tensiometer. The T4 is one of our bestselling tensiometers because it’s robust, precise, and easy to use, all at the same time. More usable than other tensiometers, it provides superior quality data and remains one of the most reliable instruments in the world for year-round outdoor monitoring. Plus, the T4’s external refilling tube and simple installation save you an incredible amount of time and effort. On top of all that, the tensiometer is highly responsive.  It reacts much faster to changing soil conditions than lower-quality tensiometers, enabling you to measure even the most minute changes in soil water potential.

It’s not immortal, but almost

Specifically designed for field use, the T4 ceramic and shaft are engineered to be virtually indestructible when it comes to harsh weather. The combination of this unbreakable and frost-resistant special ceramic and the new, impact-resistant shaft make the T4 a tensiometer you can rely on year after year in every season. And the T4 Tensiometer has a high accuracy of ±0.5 kPa, giving you peace of mind.

No removal? No problem.

We’ve outfitted the T4 with an external refilling tube. No more pulling the tensiometer out of the ground. When it’s time to refill, the T4 can be filled externally without ever having to remove it, saving you considerable time and hassle.

Pain-free installation

To save you even more time and effort, the T4 comes with a perfectly-sized auger to ensure as little soil disturbance as possible.  For spot measurements in the field, just auger a hole and insert the tensiometer.  It’s that easy.  For long-term measurement, the T4 connects to the Infield 7 or any Campbell Scientific data logger.

A tensiometer for all seasons

At METER, we know soil tensiometers. We’ve sold over 10,000 across the span of a quarter century, so we’re confident that if you need a precise, easy, and reliable field tensiometer with outstanding year-round performance, you can rely on the T4.  Its robust, frost-resistant design will never leave you in the cold.

Ceramic cup

High-strength special ceramic with homogeneous porosity
Length: 60 mm
Diameter: 24 mm

Temperature shift

Temperature-compensated, typical shift 0.5% FS over 20K
Stability typical shift < 0.5% p.a.

Shaft options

Various lengths available (standard 300 mm)
Diameter: 25 mm
Material: acrylglass 19/25 mm
**Please indicate shaft length on your order**


Piezoresistive pressure-transducer
Max. overpressure: ± 300 kPa

Output signal

100 kPa = -100 ± 3 mV
-85 kPa = 85 ± 3 mV
at 10.6V excitation

Galvanic sensor insulated from soil water, signals analog and continuous
Accurate values according to the calibration certificate
Impedance: ~.5 kOhm

Measuring pinciple

Soil water tension, transmitted via ceramic cup into the tensiometer, onto the water and pressure transducer, giving a continuous analog signal

Electronic principle

Asymm. Wheatstone full bridge

Power supply

10.6 VDC (5 – 15 VDC), stabilized


+100 to -85 kPa


0.1 kPa


± 0.5 kPa

Current consumption

~1.3 mA (at 10.6 V)

Data logger compatibility

Campbell Scientific, Infield 7


1.5 m: 4-pin plug M12
**Please indicate cable length on your order!**


METER uses UV-resistant, durable materials for long-term field studies. Seals and screw connectors are watertight according to IP68.

T4 Tensiometer Manual


TensioLINK Guide