Tested Products

Soil Moisture-based Controllers

Soil moisture-based controllers shut off the irrigation system when the ground is already wet, preventing overwatering. These smart controllers use a probe to measure moisture at the root zone. The system compares this reading to the recommended moisture level for the plant, soil type and other variables that were programmed in when the controller was first installed.

If the amount of moisture in the soil meets or exceeds the target level, the controller overrides the irrigation system. When the sensor detects dry conditions, it allows the system to operate as programmed. Soil moisture-based controllers can be retrofitted on installed irrigation systems.

SWAT Testing Protocol

SWAT began developing a testing protocol for soil moisture-based controllers in April 2003. Version 3.0 of the protocol was approved and adopted in August 2011. More information about SWAT protocols can be found on the Testing Protocols page.

Product Testing Results

07/30/2009 — Acclima ACC-SEN-TDT
08/27/2008 — Acclima Digital TDT Sensor
07/08/2010 — Baseline BL-5315B
07/08/2010 — Baseline S-100
11/03/2008 — Decagon ECH2O EC-5
04/10/2010 — Delta-T SM200 Moisture Sensor
08/27/2008 — Irrometer Watermark
09/30/2010 — Rain Bird SMRT-Y08
08/31/2012 — UgMo ProHome PH100WS

For questions about SWAT or soil moisture-based controllers, contact the Irrigation Association via email or by calling 703.536.7080.