What is Soil Temperature Sensor | How does it work?

Introduction

A soil temperature sensor is a device used to measure and monitor the temperature of the soil. They can help you determine the best time to sow or plant your garden. Thermistors, thermocouples, thermocouple wires, and averaging thermocouples are the different types of designs used for a soil temperature sensor. They are usually packed with a digital circuitry that can connect to the internet.

Why Should You Have One?

If you are into gardening, you already know the importance of temperature in the growth of plants. You cannot let the soil to be too dry or water them on a cold day. This is where the soil temperature sensor comes in. Monitoring the temperature lets you plan. This way, you can choose what’s best for the plant.

With this sensor data, you can choose to water or do not water the plant. Modern systems can automate everything for you. If you set a threshold temperature, the digital system can turn on the watering system in your garden for you. Manufacturers even provide addon modules for you to establish a complete system.

How does it work?

The Sensing Element

A temperature sensing element usually consists of a thermistor, thermocouple, or thermocouple wires. A thermistor is a temperature-dependent resistor. The resistance of a thermistor increases with temperature. A sensor has additional circuitry to convert the voltage signal into its temperature equivalents.

A thermocouple or thermocouple wires, on the other hand, are a couple. There will be 2 probes like elements made of different metals. Each probe or wire acts as an electrode and measures the voltage difference between them. The voltage difference between the wires is proportional to the temperature. An averaging thermocouple uses more than one pair of probes and averages out the voltage reading.

The Computational Part

The data from these sensing elements are voltage readings. There is digital circuitry in the backend that converts this data. This digital circuitry converts the voltage reading from the sensing element into relevant temperature readings based on the programming.

Advanced systems come with Wi-Fi modules as well. Some sensors even let the plant tweet they are thirsty when the soil is too dry. These sensors contribute to the large army of the Internet of Things(IoT). A temperature sensor can help you in building up a garden the right way.