Soil Moisture
General Description
The ALTA® Wireless Soil Moisture Sensor measures soil moisture tension and soil temperature.
Key Features
Reports matric potential (soil water tension) which is the best indicator of water availability in the soil.
Moisture Range: 0 to 240 centibar (kPa)
Moisture Resolution: ~0.3 centibar or kPa
Temperature Accuracy: +/- 1.0°C (1.8°F)
Temperature Resolution: 0.1°C
Configurable thresholds for critical condition monitoring
Principles of Operation
The ALTA Wireless Soil Moisture Sensor uses a resistive granular matrix element to accurately measure the soil's matric water potential (soil moisture tension). It also measures accurate soil temperatures. The sensor takes its measurements based on a user-configurable time interval or Heartbeat. On every Heartbeat, the soil moisture element takes a resistive measurement within a defined and consistent internal matrix material. The sensor also uses a temperature element on the end of the soil moisture lead to make accurate soil temperature measurements. These measurements are then sent to the gateway, making the data available in iMonnit or another approved data service.
Features of Monnit ALTA Sensors
Wireless range of 2,000+ feet through 18+ walls1
Frequency-Hopping Spread Spectrum (FHSS)
Best-in-class interference immunity
Best-in-class power management for longer battery life2
Encrypt-RF® Security (Diffie-Hellman Key Exchange + Advanced Encryption Standard (AES)-128 Cipher Block Chaining (CBC) for sensor data messages)
Sensor logs 2000 to 4000 readings if the gateway connection is lost (non-volatile flash, persists through power cycling):
10-minute Heartbeats = ~ 22 days
2-hour Heartbeats = ~ 266 days
Automatic over-the-air updates to sensor firmware (future-proof)
Free iMonnit Basic Online Wireless Sensor Monitoring and Notification System to configure sensors, view data, and send alerts via SMS text, email, and voice call
1 Actual range may vary depending on the environment and gateway.
2 Battery life is determined by the sensor reporting frequency and other variables. Other power options are also available
