How to ruggedize a capacitive analog soil moisture sensor – Ruggedizing and waterproofing the analog soil moisture sensor is necessary to ensure long life operation of the moisture sensor within real world applications. Without ruggedizing and waterproofing, a soil moisture sensor is all but guaranteed to short out when (not if) it gets wet. A rugged and waterproof soil moisture sensor increases system reliability while also lowering the total cost of ownership and reducing overall maintenance of your IoT and/or gardening systems.

Video: How to Ruggedize and Waterproof an Analog Soil Moisture Sensor for Long Life Operation

Materials Needed:

Steps to Ruggedize Moisture Sensor:

Prepare the Soil Moisture Sensor: The first step is to clean the moisture sensor with isopropyl alcohol. Next connect the analog PCB connector to the sensor. We will apply a clear urethane seal coat to protect and ultimately waterproof the components on the soil moisture sensor board. After snapping the board connector in place, place the sensor with components facing upward on top a piece of paper or cardboard. Next position a second piece of paper over the moisture sensor board covering the entire bottom of the board but leaving the board components exposed.

Coat the Soil Moisture Sensor PCB with Urethane Seal: Next, in a well-ventilated area, generously spray the first coat of clear urethane sealant over the soil moisture sensor components. Let the sensor dry for at least 30 minutes. Apply a second coat after the urethane seal dries to increase protection and let sit again for at least another 30 minutes. Next turn the sensor board over. Finally apply two separate coats of urethane sealant to the backside of the moisture sensor.

Apply a 3:1 Double Wall Adhesive-Lined Heat Shrink: Now place a strip of double walled adhesive lined heat shrink over the sensor components previously protected with a double coat of urethane sealant. Take a heat gun to heat up the heat shrink. Be sure to apply enough heat to melt the glue adhesive lining the heat shrink. This will ensure further waterproofing for your newly ruggedized soil moisture sensor. While still hot, firmly press the heat shrink together to seal the opening near the connector wires as shown in the video above.

Now you have ruggedized and waterproofed your analog soil moisture sensor.

You can also purchase this ruggedized and waterproof analog soil moisture sensor here in the Adosia IoT Store.