Measuring success.

Critical assessments for IoT applications.

Gardener using mobile app checking monitoring soil moisture with smartphone

Sensors & Actuators

Sensors and actuators are everywhere. They are in the ocean tracking sea temperature and currents. They are out in the farmland tracking soil conditions and predicting the optimal fertilization levels to produce the best possible crop. They are on your wrist as you sleep, sensing your heart rate and rhythm and reporting the analysis to your smartphone to help you learn to sleep better. Sensors are essential to all IoT solutions, with actuators not far behind.

What is a sensor?

Ultrasonic sensor on the table close up.

Put simply, sensors are the measuring tools that collect data and reports it to a “node” (usually a small physical device that connects one or more sensors to a network, which is often wireless). The node then takes that data and sends it over its network to the application. Let’s say you are wanting to monitor the water pressure in a pipe. It’s the sensor that measures the pressure and the node that reports the pressure back to the IoT application. Sensors and nodes are key pieces of a typical IoT solution.

Among the many enablers for the rapid growth of IoT are the improvements in sensor technology which have increased reliability and reduce size, power requirements and cost. Consider that a GPS used to be cumbersome and expensive, and now we all carry them around in our pockets (along with a gyroscope, a magnetometer, biometric sensors, an accelerometer and more). The miniaturization and proliferation, the lowered power requirements, and the significantly lowered cost of sensors are all responsible for the emergence of IoT solutions.

What is an actuator?

An actuator operates in a similar way as a sensor, but in the reverse direction. The node receives data from the application over the network it’s connected to and sends a signal to the actuator, which then turns that signal into physical action. Back to our pipe pressure example, let’s say you want to shut off the water if the pressure is too high. It’s the actuator that physically turns the valve to shut off the water.

Sensors and actuators often (but not always) work together in IoT to enable all types of IoT applications.