# Soil Moisture and Temperature ### How the Sensors Work The 3D-PAWS system supports two types of soil moisture sensors for monitoring subsurface conditions: the **Tinovi PM-WCS-3-I2C** and the **Tinovi SOIL-MULTI-5-I2C**. Both use non-contact capacitive sensing technology to measure the **volumetric water content (VWC)** and **temperature** of the soil. This approach minimizes corrosion and provides stable, long-term performance compared to traditional resistive sensors. The **PM-WCS-3-I2C** measures soil moisture and temperature at a single depth and communicates via an I2C interface. Up to eight sensors can be connected using a Grove I2C Multiplexer (TCA9548A), allowing simultaneous monitoring at multiple depths or locations. The **SOIL-MULTI-5-I2C**, by contrast, measures VWC at five depths (10 cm, 20 cm, 30 cm, 40 cm, and 50 cm) and temperature at two depths (10 cm and 50 cm) along a single probe. Each level provides an averaged reading representative of conditions at that depth. Together, these sensors enable the 3D-PAWS system to produce detailed profiles of soil moisture and temperature, improving understanding of infiltration, root-zone processes, and overall soil water dynamics. #### **Applications** The soil moisture sensors are ideal for hydrological, agricultural, and environmental monitoring applications. They provide key data for studying soil-water balance, infiltration rates, root-zone moisture dynamics, and soil temperature gradients. When deployed as part of the 3D-PAWS network, these sensors support research on land–atmosphere interactions and improve understanding of how soil moisture influences weather, climate, and ecosystem processes. ### Instruction Slides for Adding the Tinovi PM-WCS-3-I2C {% embed url="" %} ### PM-WCS-3-I2C Installation Tool {% embed url="" %} ### Instruction Slides for Adding the Tinovi SOIL-MULTI-5-I2C {% embed url="" %}