> For the complete documentation index, see [llms.txt](https://3dpaws.comet.ucar.edu/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://3dpaws.comet.ucar.edu/building-3d-paws/adding-additional-instruments/soil-moisture-and-temperature.md).

# 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="<https://docs.google.com/presentation/d/1gtIi9yG1OnERd5IsEoB5_NCDtpoBEdC1/edit?ouid=102244773211795243299&rtpof=true&sd=true&usp=sharing>" %}

### PM-WCS-3-I2C Installation Tool

{% embed url="<https://docs.google.com/presentation/d/1yaE_M_TYDpAXBLXzfsWneeV_LayQAZ7u/edit?ouid=102244773211795243299&rtpof=true&sd=true&usp=sharing>" %}

### Instruction Slides for Adding the Tinovi SOIL-MULTI-5-I2C

{% embed url="<https://docs.google.com/presentation/d/14ZWVra-Wjku8X4AlnEKnqbIBVQarVet6/edit?ouid=102244773211795243299&rtpof=true&sd=true&usp=sharing>" %}


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