Item no.: 1188000

Advantages at a glance

  • high accuracy
  • additional detection of soil temperature
  • independent conductivity measurement
  • compatible with existing data loggers
  • inexpensive

Please send me more information about UMP-2


The standard version of the UMP-2 sensor is designed for connection to data loggers via cable. The data logger supplies the sensor with power and stores the measured values. From the logger, the data is output via an interface cable to a laptop or via remote data transmission. This design is particularly suitable for measuring sites with several soil moisture sensors (in connection with a data logger) and long-term measurements (e.g. soil hydrological measuring sites, lysimeters).

What can the UMP-2 do?

This soil moisture sensor is waterproof potted and can be completely buried for deep or horizontal installation. The UMP-2 is made of plastic or stainless steel, while the measuring rods (antennas) are basically made of stainless steel. Data acquisition is both analog and digital (RS485). This makes it possible to integrate the probe into other bus systems.

The UMP-2 determines soil moisture by measuring the relative permittivity (dielectric constant, εr) of the soil. In addition, you can also use it to measure soil temperature (°C) and electrical conductivity (mS/cm). The latter is determined independently of soil moisture via an additional circuit. Since the relative permittivity is salt-dependent, you will get too high a permittivity if the conductivity is too high. The independently determined electrical conductivity can therefore be used for its correction.

Measurement frequency for water content: 120 MHz
Antenna length: 50 mm
Antenna diameter: 3 mm
Water content measurement range: 0 … 100 % Vol. water content
Water content accuracy: ±2%
Dielectric coefficient ε measurement range: 0 … 80
Electrical conductivity measurement range: 0,001 … 5mS/cm
Optional data extension to 40mS/cm possible
Electrical conductivity accuracy: ±1%
Soil temperature measurement range: -40 … +60°C
Soil temperature accuracy: ±0.5°C (across the entire temperature range)
Measurement volume: 1000 ml
Working temperature range: -40 … +60°C

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