WET150 Kit Sensor Kit for Moisture and Salinity in soils and substrates

-  This WET150 Kit is a portable and rugged solution for researchers who need to assess moisture and salinity conditions in soils and substrates.

-  The WET150 Kit makes fast soil & substrate measurements in three crucial variables that influence plant growth:
-  moisture content
-  temperature*
-  electrical conductivity (EC) – a strong indicator of the general nutrient level.
*Delta-T recommends that the WET150 Kit is used as a portable hand held sensor only in well-equilibrated environments where the air temperature doesn’t differ significantly from the soil/substrate temperature.

WET150 Sensor

± 0.03 m3.m-3 (3%)

See graph below this table

± (3% of reading + 0.8 ε’)

1 → 40

± (10mS.m-1 + 6%) 

± 0.5°C
(0°C to +40°C range)
± 0.7°C
(-20°C to +60°C range)

± 5% of reading

40 → 80

Full range:

0 to 1.0 m3.m-3

See graph below this table

for ECp ≤ 800 mS.m-1

1 → 40

from 0 to 1200 mS.m-1

Full range:

-20°C to +60°C

Accurate range:

0.05 to 1.0 m3.m-3

ECb 0 to 500 mS.m-1

for ECp ≤ 500 mS.m-1

40 → 80

Accurate range:
0°C to +40°C

SDI-12 protocol 1.3 (www.sdi-12.org)
Providing water content, pore water conductivity, and temperature - together with base readings of permittivity and bulk conductivity.
Outputs are exceptionally configurable.

Operating voltage: 6 to 20 Volts

Current consumption (typical values powered from 12 Volts):
Active sensing: 22 mA average over 12 ms (average includes short peaks at 45 mA)
Active results computation: 2 mA over 188 ms
Idle: <0.5mA

IP68, - 20 to + 60°C

~55 x 70 mm diameter

Sample volume is weighted towards soil immediately surrounding the rods

Overall: 143 x 40 mm dia

Rods: 51 mm x 2.5 mm dia

Weight: 77g (excl. cable)

Individual sensors are interchangeable

Recalibration advised every 5 years (depending on use)

The WET150 Sensor comes complete with calibrations for mineral and organic soils plus perlite, coir, peat, and mineral wool substrates

Notes: [1] The WET150 has been carefully optimised to provide accurate readings in soils and substrates - readings taken in water or air may not meet the full specification. [2] The ECp contour map is based on measurements from 30 sensors at 20°C in NPL* traceable media. Calculated ECp readings are derived from the Hillhorst equation, using the generalised “mineral” soil calibration and the default soil parameter = 4.1 * NPL is the UK's National Metrology Institute, developing and maintaining the national primary measurement standards.

WET150 Meter

This Kit comprises of:
-  WET150 Sensor.
-  WET150 hand-held readout meter.
-  Carrying case.
-  Spare batteries & user guide.

When it is correctly connected and tightened, the kit’s cables and connectors are completely watertight.
The handheld WET150 Meter displays volumetric water content as % volume and EC in milliSiemens/metre.

-  The WET150 Meter is a lightweight and easy to use readout-only device (no data recording or other complications). Operation of the kit is straightforward – the user inserts the WET150 into the soil or substrate and presses the “Read” button on the meter to take and display the measurement.

-  The WET150 Sensor comes complete with calibrations for mineral and organic soils plus perlite, coir, peat, and mineral wool substrates soils.

Applications in Research

The WET150 Kit can be used for precise reliable readings of soil/substrate water content.
However, the inclusion of electrical conductivity (pore water conductivity ECp) measurement makes it particularly well suited to horticultural research in the areas of fertigation, precision irrigation, and soil salination monitoring.