What is a sensor?

Discover what a sensor is, how sensors work, and their applications in industries like healthcare, automotive, and IoT. Learn about different types of sensors and their role in modern technology.

Sensors: definition and function

Today, you are surrounded by sensors. Whether in a vehicle, in your home, in the office, or an industrial setting, there are sensors controlling various processes around you. There are both wired and wireless sensors that control processes that improve life, efficiency, and productivity. So, what are sensors and what are their applications? Find out the answers in this guide.

How sensors work: the basics

Sensors have become the fundamental building blocks of data acquisition systems (DAQ). They are also referred to as transducers. The main components of a sensor include:

  • Sensors
  • Analog to digital converter
  • Signal conditioning
  • Computer system and DAQ software

Whether it is environmental sensors or wireless sensors, they work by converting different forms of physical energy into electrical energy. They feature microcontrollers that read changes in the physical environment.

Types of sensors and their applications

Sensors can be classified into two different forms of categories as discussed below:

Common types of sensors

Overall, sensors are classified into four major categories. These include:

  • Analog sensors
  • Digital sensors
  • Passive sensors
  • Active sensors

In terms of applications, sensors can be classified into many different types. These include:

  • Accelerometer sensors: They feature an electromechanical sensor to measure static or dynamic acceleration. The sensor works by converting the displacement of a mass into a digital electrical signal that can then be processed.
  • Temperature sensors: A temperature sensor detects thermal parameters. Once the thermals are detected, the sensor will provide signals to the device’s inputs. There are further sub-types to these sensors. Some of these sensors require physical contact with the target to measure the temperature. On the other hand, non-contact sensors use convection or radiation for this purpose.
  • Proximity sensors: A proximity sensor can use different principles to detect the presence/absence of an object. It works without making physical contact. There are different sub-types that include capacitive, ultrasonic, inductive, and optical sensors. The object’s color, transparency, or surface texture does not affect these sensors’ readings.
  • Gyroscope sensors: These sensors work based on the forces of gravity and angular momentum. The forces are used to measure orientation and rotational motion. The sensor is generally known by its spinning rotor that provides angular momentum. They can sense angular velocity whenever the frame rotates. Angular velocity is measured in terms of revolutions or degrees per second. The readings are then converted into a digital electrical signal.
  • Imaging sensors: Imaging sensors are also referred to as vision sensors. They are designed to detect the presence of objects or colors. Their sensor technology converts the captured data into a visual image to be displayed. A single sensor is capable of performing multi-point inspections. The technology uses both image acquisition and processing functionalities.
  • Infrared sensors: These sensors can detect or emit infrared (IR) radiations to sense specific environmental characteristics. These characteristics can be heat or motion. The sensor technology is based on the concept that any object above 0 degree temperature emits heat energy in IR form. The sensor typically features an IR LED and photodiode that work together to create a photo-coupler. A sub-type, passive IR sensor, features a couple of pyroelectric sensors for detecting heat energy.
  • Position sensors: There are three types of position sensors, including angular, rotary, and linear sensors. They use contact and non-contact sensor technology. There are further types of position sensors, including linear potentiometers, displacement sensors, and eddy current sensors.
  • Radiation sensors: These environmental sensors detect and measure radiation levels. They are also referred to as radiation detectors and can detect x-rays and gamma rays.
  • Humidity sensors: A humidity sensor measures the presence of water in the surrounding air. This sensor typically has a thermistor and humidity-sensing element. It works by detecting the changes in temperature or electrical currents in the surrounding air. There are further sub-types that include thermal, capacitive, and resistive sensors.
  • Motion sensor: A motion sensor both detects and measures movement. It has different sub-types, such as microwave, passive infrared, hybrid, tomographic, and ultrasonic sensors. 
  • Ultrasonic sensor: This sensor is designed to determine the distance to an object. An ultrasonic sensor works by emitting high-frequency waves and measuring the time taken for the waves to return after reflection. Some of these sensors rely on piezoelectric ceramics to send and receive waves.

There are many other types of sensors, including pressure sensor, photoelectric, level, electrical, and flow sensor.

Applications of sensors

Find out how these different sensor technologies are used in their field of application:

  • Accelerometer sensors: These sensors are used in different industries and sectors. They are more commonly used in navigation and control applications.
  • Temperature sensors: A temperature sensor is found in the HVAC system or microwave in your home. It is also found in something as complex as an aircraft or an industrial machine. 
  • Proximity sensors: The proximity sensor finds application in different areas. It is most commonly used in safety systems, automation, and operational controls. It is widely used in printing, molding, food processing, packaging, and chemical processing.
  • Gyroscope sensors: These sensors are widely used in automobile electronic stability control systems and camera-shake detection systems. 
  • Imaging sensors: These sensors find application in processes involving pass/fail tests, measurements, and product quality control. 
  • Infrared sensors: These sensors are widely used in search/track systems, radiation measurement, gas detection, and thermal imaging. 
  • Radiation sensors: This sensor technology is widely used in tasks involving radiation measurement, search, and protection.
  • Motion sensors: The motion sensor is commonly used in office and restroom applications and home/business security systems. Other areas include automation, computing systems, robotics, smart vehicles, and embedded systems.

IoT in advancing sensor technology

IoT sensors and their impact

IoT sensor technology involves hardware for detecting environmental changes and collecting data. It works as the connection between the physical and digital medium. These sensors are capable of measuring pressure, temperature, and motion. They can share information across different networks and enable devices to interact with each other. 

IoT sensors gather real-time data and empower automation, predictive maintenance, and data-based insights. This makes them a must-have for IoT applications.

Some of the different types of IoT sensors include:

  • Temperature sensors
  • Pressure sensors
  • Proximity sensors
  • Gas & chemical sensors
  • Water quality sensors
  • Smoke sensors
  • Infrared sensors
  • Motion sensors
  • Accelerometer sensors
  • Level sensors
  • Humidity sensors
  • Gyroscope sensors
  • Optical sensors

These sensors have become essential across a wide range of industries including retail, manufacturing, agriculture, and healthcare. A few common examples are as follows:

  • Smart homes: Temperature, humidity, and motion sensors regulate indoor comfort, enhance security, and enable better lighting controls. IoT sensors make your home more comfortable and energy-efficient.
  • Retail: The infrared sensor and proximity sensor are crucial in inventory management. They also help analyze in-store customer behavior and product condition monitoring.
  • Healthcare: Ongoing vitals monitoring can assist healthcare providers offer remote care. It can help enhance patient outcomes, and detect early warning signs.
  • Manufacturing: The proximity sensor, temperature sensor, and level sensor are widely beneficial for detecting anomalies, tracking machinery performance, and predicting maintenance needs.

Future of sensor technology

Sensor technology has a massive growth potential in the future. Many other technology sectors and industries rely on sensors. This means sensors can play a pivotal role in the evolution and facilitation of different industries. Future sensor technologies are expected to be more intelligent and accurate.

Some of the key developments that will take place in sensor technology in the future include:

  • Growing demand for IoT sensors
  • Smart sensors will power new applications to boost efficiency, reduce latency, analyze data locally, and empower real-time decision-making
  • AI-enabled sensors will help find new opportunities in the fields of agriculture, medicine, and industrial control systems to name a few.
  • Wearable sensors will play a more important role in tracking health and fitness levels
  • Biometric sensors will become more feature-rich to enhance authentication and security
  • 5G-enabled sensors will help improve data transmission speeds

IoT sensor technology can help enrich operational effectiveness and efficiencies in many areas in the future. 

 

Frequently Asked Questions

Q. How do sensors work?

Sensors work by converting a physical action into electrical signals to help measure the physical action. Sensors send out electrical signals for further processing.


Q. What are the different types of sensors?

Sensors can be classified into four main categories. These include analog, digital, passive, and active.


Q. What industries use sensors?

Sensors are used in almost all types of industries. These include, but are not limited to agriculture, manufacturing, construction, healthcare, retail, fleet management, hospitality, energy, and automotive. 


Q. Why is sensor calibration important?

Sensor calibration is important for verifying the sensor’s precision in measurements. 


Q. How do IoT sensors work?

IoT sensors work by detecting changes in the environment before gathering data. The data is then converted into digital form. They share the data across networks, enabling devices to interact with each other.


Q. What is a smart sensor?

A smart sensor captures input from the surrounding environment and relies on built-in computing information to conduct preset functions when certain inputs are detected. The sensor also processes data before it is passed on.