A Sensor is a characteristic of any device or material to detect the presence of a particular physical quantity. The output of the sensor is a signal, which is converted to human readable form. It performs some function of input by sensing or feeling the physical changes in the characteristics of a system in response to stimuli.
The input can be light, heat, motion, moisture, pressure, or any other environmental phenomena. sensors play a pivotal role in IoT which will make an ecosystem for collecting, analyzing, and processing data about a specific environment so that it can be monitored, managed, and controlled more easily and efficiently. Sensors bridge the gap between the physical world and the logical world.
Transducer : It converts the signal from one physical form to another physical form. it is also called energy converter. For example, microphone converts sound to electrical signal . It is based on the principle of conservation of energy.
Types of Sensors
We live in the world of sensors, there are different types of sensors in our homes, offices, cars etc. by working to make our lives easier by turning on the lights by detecting our presence, adjusting the room temperature, detect smoke or fire, make us delicious coffee, and automatic door closing and so on. here we will discuss types of sensors one by one in detail:
- Temperature sensors: Monitoring temperature of used devices in industrial applications. it is used to measure temperature. this can be air temperature, liquid temperature or the temperature of solid. It can be analog or digital. In an Analog Temperature Sensor, the change in the Temperature correspond to change in its physical property like resistance or voltage. LM35 is a classic Analog Temperature Sensor. In Digital Temperature Sensor, the output is a discrete digital value, DS1621 is digital sensor which generates 9 bits temperature data.
- Accelerometer sensors: It measures the rate of change of velocity and this sensor generate magnitude and acceleration of the acceleration. Accelerometer sensor sensor ADXL335 provides 3 axes (X,Y, and Z) values in analog voltage. it is used in car electronics, ships, and agricultural machines.
- Alcohol sensors: as the name suggests it detects alcohol. Usually, alcohol sensors are used in breathalyzer devices, which determine whether the person is drunk or not. Law enforcement personnel uses breathalyzers to catch drunk-and-drive culprits.
- Radiation sensors: Radiation Sensors/Detectors are electronic devices that sense the presence of alpha, beta, or gamma particles and provide signals to counters and display devices. Radiation detectors are used for surveys and sample counting.
- Position sensors: Position Sensors are electronic devices used to sense the positions of valves, doors, throttles, etc. and supply signals to the inputs of control or display devices. Key specifications include sensor type, sensor function, measurement range, and features that are specific to the sensor type. Position sensors are used wherever positional information is needed in a myriad of control applications. A common position transducer is a so-called string-pot, or string potentiometer.
- Gas sensors: It measures and detects concentration of different gases which is present in the atmosphere or any other environment.
- Torque sensors: This sensor is used for measuring the rotating torque and it is used to measure the speed of the rotation.
- Optical sensors: it is also called photosensors which can detect light waves at different points in the light spectrum including ultraviolet light, visible light, and infrared light. it is extensively used in smartphone, robotics and Blu-ray players.
- Proximity sensors: This sensor is used to detect the distance between two objects or detect the presence of an object. it is used in elevators, parking lots, automobiles, robotics, and numerous other environment.
- Touch sensors: Touch sensing devices detect physical contact on a monitored surface. Touch sensors are used extensively in electronic devices to support trackpad and touchscreen technologies. They’re also used in many other systems, such as elevators, robotics and soap dispensers.
- Image sensor: it is used for distance measurement, pattern matching, color checking, structured lighting, and motion capture and it is also used in different applications such as 3D imaging, video/broadcast, space, security, automotive, biometrics, medical, and machine vision.
FAQs on Types of Sensors
Q.1: What is Active sensors and Passive sensors?
Answer:
Active Sensors are those which require an external excitation signal or a power signal. Passive Sensors, on the other hand, do not require any external power signal and directly generates output response. The other type of classification is based on the means of detection used in the sensor.
Q.2: Which sensor is used to detect the speed of the particular object at any instant?
Answer:
Speed detecting sensors which is also called Motion sensors are used to sense the physical movement in physical space.
Q.3: What are the classification of sensors?
Answer:
Sensor can classified as:
1. Active sensor and Passive sensor.
2. Analog and Digital sensor.
3. Scalar and Vector sensor.