Build a Water Sensor Circuit for the Tree

By Amy Cowen on December 9, 2022 6:00 AM

With a bit of creative engineering, a simple circuit can do double-duty as a fun decoration and a helpful water-level monitor!

A reindeer ornament with a circuit to monitor the water level for a tree

Creative Engineering

When faced with a problem, engineers come up with innovative and creative solutions! Keeping a cut holiday tree watered is important for preserving the life of a fresh tree, especially during dry winter days. With a bit of crafty science and engineering, one of our staff scientists added a circuit with a sensor to a simple holiday ornament to help him keep track of when his tree needs water.

If the tree is low on water, the reindeer ornament lights up.

Making Connections

Students can experiment with sensor-based science and circuit building using the Sensors Kit. To build a monitor similar to the one used in our engineer's reindeer ornament, students can explore the circuit shown in the Green Technology: Build an Electronic Soil Moisture Sensor to Conserve Water electronics project.

You can place your finished ornament anywhere you want on the tree, provided the probes can reach the water in the tree stand. Use duct tape or heavy-duty tape to secure your probes to the stand at the level you want for the light to go on or off. For an overview of the setup, see Figure 3 in the project.

(Note: to build an "ornament" monitor similar to the one shown, using a soldering iron is recommended for a more durable circuit that can hang on a tree.)

Learn more about the Electronic Sensors Kit