Creating an outdoor plant box with a built-in sulfur dioxide (SO₂) detector is a fantastic way to combine gardening with environmental monitoring. This DIY project not only adds greenery to your space but also helps track air pollution levels. Here’s a step-by-step guide to building your own:

Materials Needed:

- Untreated cedar or redwood planks (for durability)

- Wood screws, drill, and saw

- Waterproof sealant

- Sulfur dioxide sensor (e.g., electrochemical SO₂ detector)

- Small waterproof enclosure for the sensor

- Basic wiring tools (if the sensor requires power)

Step 1: Design the Plant Box

Sketch a simple rectangular box with dimensions suited to your space (e.g., 24"L x 12"W x 12"H). Cut the wood accordingly and assemble the box using screws, leaving drainage holes at the bottom.

Step 2: Install the SO₂ Detector

Mount the sulfur dioxide sensor inside a waterproof enclosure and attach it to one side of the plant box. Ensure it’s positioned to avoid direct soil contact but exposed to airflow. For powered sensors, discreetly run wiring through a small drilled hole.

Step 3: Seal and Protect

Apply a non-toxic waterproof sealant to the wood to prevent rot. Let it dry thoroughly before adding soil.

Step 4: Plant and Monitor

Fill the box with soil and add your chosen plants. Turn on the sensor (if applicable) and calibrate it according to the manufacturer’s instructions. Regularly check readings to monitor local SO₂ levels.

Tips:

- Place the box in a sunny, open area for accurate air quality detection.

- Choose hardy plants like marigolds or lavender to complement the eco-friendly theme.

- Clean the sensor periodically to maintain accuracy.

This project merges sustainability with functionality, offering a unique way to care for both your plants and the environment. Happy building!