ECH<sub>2</sub>O 5TM

Soil Moisture and Temperature


Temperature integrated with soil moisture

The 5TM delivers temperature, measured by an onboard thermistor, along with accurate volumetric water content.

Engineered for accuracy

The 5TM determines volumetric water content (VWC) by measuring the dielectric constant of the soil (or other media) using capacitance/frequency domain technology. The sensor uses a 70 MHz frequency, which minimizes salinity and textural effects, making the 5TM accurate in most soils and soilless media. Factory calibrations are included for mineral soils, potting soils, rockwool, and perlite.

Easy installation

The 5TM’s small size makes it easy to install in the field and the greenhouse. This robust sensor can be pushed directly into undisturbed soil to ensure good accuracy.

Plug and read

Get straight to the data with the new ZL6 data logger. Just install the 5TM, plug it into the ZL6, set the clock and measurement intervals, and start logging data. No programming required.

Easy integration

The 5TM comes standard with both serial and SDI-12 communication options, meaning easy integration with systems manufactured by other companies.

Advantages of the 5TM

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  • Measures VWC and soil temperature
  • SDI-12 compatible
  • Easy installation
  • Plug and play with METER data loggers
  • Use with the ZL6 data logger to collect data remotely
  • 70 MHz frequency minimizes salinity and textural effects
  • Factory calibrations are included for mineral soils, potting soils, rockwool, and perlite



Volumetric water content (VWC)

Mineral soil calibration: 0.0–1.0 m3/m3
Soilless media calibration: 0.0–1.0 m3/m3
Apparent dielectric permittivity (εa): 1 (air) to 80 (water)
0.0008 m3/m3 from 0%–50% VWC
Generic calibration: ± 0.03 m3/m3 typical
Medium-specific calibration: ±0.02 m3/m3
Apparent dielectric permittivity (εa): 1–40 (soil range), ±1 εa (unitless)
40–80, 15% measurement


Range: –40 to +60 °C
Resolution: 0.1 °C
Accuracy: ±1 °C

Measurement volume

See comparison article



DDI serial or SDI-12 communication protocol

Data logger compatibility

METER data loggers (ZL6, EM50/60 series) or any data acquisition systems capable of 3.6- to 15.0-VDC power and serial or SDI-12 communication



Length: 10.9 cm (4.3 in)
Width: 3.4 cm (1.3 in)
Height: 1.0 cm (0.4 in)

Prong length

5.0 cm (1.9 in)

Operating temperature range

Minimum: –40 °C
Maximum: +60 °C

NOTE: Sensors may be used at higher temperatures under certain conditions; contact Customer Support for assistance.

Cable length

5 m (standard)
75 m (maximum custom cable length)

NOTE: Contact Customer Support if a nonstandard cable length is needed.

Connector types

3.5-mm stereo plug connector or stripped and tinned wires


Supply voltage (VCC to GND)

Minimum: 3.6 VDC
Maximum: 15.0 VDC

Power line slew rate

Minimum: 1.0 V/ms

Current drain (during measurement)

Minimum: 0.5 mA
Typical: 3.0 mA
Maximum: 10.0 mA

Current drain (while asleep)

Typical: 0.03 mA

Power-up time (DDI serial)

Maximum: 100 ms

Power-Up Time (SDI-12)

Minimum: 100 ms
Typical: 150 ms
Maximum: 200 ms

Measurement duration

Typical: 150 ms
Maximum: 200 ms


Manufactured under ISO 9001:2015
EM ISO/IEC 17050:2010 (CE Mark)

California requires the following notice:

⚠️ WARNING: This product may contain chemicals including ethylene glycol, lead, nickel, styrene and cadmium, which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov


Have a question or problem? Our support team can help.

We manufacture, test, calibrate, and repair every instrument in-house. Our scientists and technicians use the instruments every day in our product testing lab. No matter what your question is, we have someone who can help you answer it.

Phone US: +1 509-332-5600
Phone Europe: +49 89 12 66 52 0


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