A sensor is a device that detects and responds to input like light, heat, moisture, motion, pressure, or other environmental phenomena obtain from the physical environment.Further, the output signal converted into a human readable form at the sensor location to read or proceed.
What is Sensor?
Sensor is a broad term that refers to a device or component used to detect, measure, or monitor physical quantities or environmental conditions. Hence, the sensors are commonly used in various fields, including engineering, electronics, physics, biology, and many others. Accordingly, they convert physical phenomena, such as light, temperature, pressure, motion, or chemical properties, into electrical signals that can be measured, analyzed, or used for control purposes.
Moreover, the sensors play a important role in the internet of things (loT). They create an ecosystem to collect and process data about a particular environment so that it can be monitored, managed and controlled more easily and efficiently.loT传感器用于房屋、田地、汽车、人工智能rplanes, industrial settings and other environments.
Types of Sensors
The sensors can be classified in various ways. One of the common classifications is either active sensor or passive sensor. The explanation is as below –
Active Sensor
It needs an external power source to respond to environmental input and to generate output. For example – To provide earth’s atmospheric or meteorological data the sensors of weather satellites need external source of energy.
Passive Sensor
它不需要任何外部电源recognize environmental input. But it is depended on the environment itself for its power and uses the sources like light or thermal energy. For example – mercury-based thermometer. The mercury expands and contracts with response to changing temperatures that causes the level to be higher or lower in the glass tube. To view the temperature, there is a external markings provided for human-readable gauge.
Other types of sensors are – seismic andinfrared light sensorswhich are available in both active and passive forms. Based on the output,the sensor can be classified as analog or digital.
Analog Sensors
It converts the environmental input into output analog signals that are continuous and changes. Example – Thermocouples that are used in gas hot water heaters. The thermocouple gets heated continuously by the water heater’s pilot light. And when the pilot light turns off, the thermocouple cools and sends a different analog signal to indicate the gas to turn off.
Digital Sensors
They convert the environmental input into discrete digital signals which are transmitted in a binary form (0’s and 1’s). Digital sensors are most commonly used in most of the industries, replacing analog sensors in many situations. For example – digital sensors are used to measure humidity, temperature, atmospheric pressure, air quality, etc.
Unlike active and passive sensors, other types of sensors are available in both analog and digital sensors, they are – thermal sensor and pressure sensor. The environment in which the sensor will operate are basically finds for the best option.
Classification of Sensors
Sensors are mainly classified by the type of environmental factors they monitor. Below are some of the examples explained –
Accelerometer
This sensor detects the changes in gravitational acceleration by making it possible to measure tilt, vibration and acceleration. This sensor is widely used in industries from consumer electronics to professional sports to aerospace and aviation.
Chemical
It detects a particular chemical substance within a medium i.e, solid, liquid or gas. This chemical sensor can also be used to detect soil nutrient levels in a crop field, smoke, carbon monoxide, pH levels in water body, amount of alcohol in person’s breath etc. For example – an oxygen sensor in a car’s emission control system will monitor the gasoline-to-oxygen ratio via a chemical reaction that generates voltage.
Humidity
They detect the level of water vapors in the air to decide the relative humidity. The relative humidity is dependent on the air temperature as these sensors mostly include temperature readings. Moreover,industries like agriculture, manufacturing, data center’s, meteorology, heating, ventilation and air conditioning, the sensors are used widely.
Level
This sensor can regulate the level of physical substance like water, fuel, coolant, grain, fertilizer or any kind of waste. For example – motorists depend on their gas level sensors in order to ensure not to end up stranded on the side of the road. This level sensors are also used in tsunami warning systems.
Motion
The motion detectors have the capacity to sense physical movement in a particular space and it can be used to control lights, cameras, parking gates, water faucets, security systems, automatic door openers, etc. Hence, the sensors send out some type of energy like microwaves, ultrasonic waves, light beams which can detect when the flow of energy is interrupted by an unknown thing enters its path.
Optical
They are also called as photosensors that can detect light waves at various points in the light spectrum along with UV light, visible light and infrared light. Basically, these sensors are used in smartphones, robotics, Blu-ray players, home security systems, medical devices etc.
Pressure
They detect the pressure of liquid or gas. Pressure sensors are mainly used in machinery, automobiles, aircraft, HVAC systems etc. They also measure the atmospheric pressure by meteorology. They can also monitor the flow of gases or liquids so that the flow can regulated.
Proximity
They detect the availability of an object or decides the distance between the objects. Additionally, they are used in elevators, assembly lines, parking lots, retail stores, automobiles, robotics etc.
Temperature
They can recognize the temperature of a target medium if solid, liquid or gas. They are used in various devices and environments like – appliances, machinery, aircraft, automobiles, computers, greenhouses and farms, thermostats etc.
Touch
They are the sensing devices that detect physical contact on a monitored surface. They are mainly used in electronic devices to support trackpad and touchscreen technologies. Additionally, they are also used in elevators, robotics and soap dispensers.
Advantages of Sensors
- Sensors accelerates processes and makes them more accurate.
- They can collect process and asset data instantly.
- They monitor processes and assets accurately, reliably and more often.
- Sensors increase productivity and reduce ownership’s total cost.
- Lower energy wastage.
Disadvantages of Sensors
- Faulty information from sensor may raise serious concerns.
- Sensors are very expensive to build a control system.
- They are more likely to break down.
- Sensors can be blocked by dirt.
- The reflecting plate can be moved and hence the user might not get the signal when required.
- Sensors can be physically displaced and triggered in the wrong position.
In the modern electronic systems and in automobiles, Sensors has an important role.They also play a vital role in our everyday life as we have a need to collect information and process it for some tasks. Successful application of sensor relies on sensor performance, cost and reliability. Sensors have become common in all the sectors now a days and their use is barely used noticed.
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