Sensors are an integral part of modern living. If you are reading this article on a computer, you are most likely using a mouse, which contains an optical sensor. If you are on a smartphone, you are using touch sensors every time you touch the screen. But what exactly is a sensor?
A sensor is a device that measures physical input from its environment and converts it into data that can be interpreted by either a human or a machine. Most sensors are electronic (the data is converted into electronic data), but some are more simple, such as a glass thermometer, which presents visual data. People use sensors to measure temperature, gauge distance, detect smoke, regulate pressure and a myriad of other uses.
There are two types of electronic sensors: analog and digital. Analog sensors convert physical data into an analog signal. Analog sensors are much more precise than digital sensors, which are limited to a finite set of possible values. Below is a chart showing the difference between analog and digital signals:
Because analog signals are continuous, they can account for the slightest change in the physical variable (such as temperature or pressure). Digital signals, while following the general trend of variation, are restricted to fixed data (ones and zeros).
There are a multitude of types of sensors. In the average automobile alone, there are dozens of different types of sensors. Tire pressure sensors indicate whether a tire is flat or in need of more air. Self-driving cars such as the Tesla are equipped with ultrasonic sensors that measure the distance between the vehicle and other objects in its environment using sound waves. Home security systems use motion sensors, which detect the movement of primarily larger objects. The most commonly used motion sensor for home surveillance is called a Passive Infared (PIR) system, which detects infrared radiation in the sensor’s environment.
Sensor technology is also used frequently in medical devices. Input sensors such as myo-electrodes are used in prosthetic technology. Myo-electrodes detect electrical signal from a patient’s muscle contractions. Heartbeat sensors monitor and detect patients’ pulse, and thermometers measure temperature.
The Future of Sensor Technology
As technology develops, the use of sensors will continue to expand into every aspect of our lives. Engineers and scientists around the world will use sensors to enhance transportation systems, medical procedures, nanotechnology, mobile devices, virtual and augmented reality, and even artificial intelligence (AI).