A sensor is an electronic device that measures and monitors environmental conditions. The data recorded by these devices is usually collected by a computer, which then uses the information to take action. Sensors measure physical qualities, such as speed, and built into many devices that you use regularly.

For example, you can equip a freezer with a sensor linked to its thermostat controller. When the device senses that the temperature in the freezer has increased past the acceptable limit, it may trigger the thermostat to kick in and lower the temperature until the freezer is once again just cold enough.

Other interesting terms…

Read More about a “Sensor”

Sensor technologies have been around since the mid-1940s from when Samuel Bagno invented an ultrasonic alarm. The device sent waves all over the room, and when something interrupts those waves, an alarm goes off. Bagno was able to invent this device using his knowledge of radar technology, which mainly figured in World War II. During the war, radars detected enemy aircraft and underwater forces.

Different alarm systems used ultrasonic technology until the introduction of infrared motion sensors in the 1980s. These devices used motion sensors to detect the movement of a person or an object. These movements disturb the normal state of the sensor, thereby triggering an electronic signal.

Sensor Applications

Today, sensors have several applications in automatic lighting systems, video games, security systems, and even cellular phones. Let’s explore these uses in more detail below.

1. Automated Lighting Systems

Automated lighting systems commonly use motion sensors to automatically dim or turn off the lights when people leave a room. Some are also triggered with a touch or sound when a person is ready to sleep. In such cases, the interior lights turn off while those outside automatically turn on.

2. Video Games

Video game controllers and games, in general, have built-in motion sensors today. Video game controllers that can track the orientation and acceleration of a player became famous in 2006 with the introduction of Nintendo’s Wii Remote Controller. However, motion sensors have been in use in arcade games since the 1990s. An arcade game called “Hang-On” featured a motorbike, which a player could ride and move with his/her body.

3. Security Systems

Home security has never been the same ever since the use of sensors. Today’s security systems have motion sensors that trigger an alarm when an intruder is detected. You ideally turn these systems on when you leave your house, so they can catch potential intruders when they move. Some of them can be programmed to activate security cameras when motions are detected.

Aside from detecting intruders in your home, motion detectors can also make your everyday life easier. You can use it to:

  • Monitor your children even when they’re not in the same room
  • Track your pets’ movements, so they don’t go to certain areas of your home
  • Automatically ring the doorbell when a person is near the front door

5. Cellular Phones

Most mobile phones these days automatically change their screen orientation when you move. That’s motion sensor technology in action. Mobile devices use sensors when you play games using phone movements to control characters or game pieces.

Classifications of Sensors

Sensors come in various types, including:

  • Active sensors: Also called “parametric sensors” require an external power source to operate. Examples include Global Positioning System (GPS) and radar sensors.
  • Passive sensors: Also known as “self-generated sensors,” these generate their own electric signal and do not require an external power source. Examples include thermal and electric field sensors and metal detectors.
  • Contact sensors: Require physical contact with their stimulus. Examples include temperature and strain gauge sensors.
  • Noncontact sensors: Don’t require physical contact, which include optical and magnetic sensors and infrared thermometers.
  • Absolute sensors: Got their name by providing absolute readings of their stimuli. An example would be a thermistor that always measures the exact or absolute temperature reading.
  • Relative sensors: Provide fixed or variable measurements, such as a thermocouple, which measures temperature differences, not the actual temperature.
  • Analog sensors: Produce continuous analog output signals that are proportional to measurements. Examples include accelerometers, pressure sensors, and light and sound sensors.
  • Digital sensors: Also go by “electronic or electrochemical sensors,” these convert data transmission digitally. Examples include digital accelerometers and pressure and temperature sensors.
  • Miscellaneous sensors: All other sensors that don’t fall under any of the categories belong here. These include electric, biological, chemical, radioactive, and other sensors.

Sensor technology has come a long way since Bagno created the first-ever ultrasonic alarm. Today, sensor applications make our everyday lives better. Even items as trivial and ordinary as our mobile devices make use of sensors.