In this blog, we will discuss the IR sensor working standard and its applications.
When you want to create a smart home, you can use an Infrared Sensor IR sensor Module. These sensors can detect objects with the help of an infrared transmitter and receiver. The majority of these sensors cost less than a dollar each. You can adjust the sensitivity of the IR sensor using a potentiometer. If you want to make it more sensitive, you can add a second one.
The IR sensor module has three pins: GND, Vcc, and a signal pin. The Signal pin can be connected to an analog or digital pin. It is usually recommended to use a digital reading, as this will enable you to see the activity of the sensor. Upon being triggered, the sensor will read either a 0 or a 1 depending on which version it is.
The IR sensors have two main types, imaging and non-imaging. The latter type uses a laser diode as a light source. Infrared sensors have two types of output: the beam from a laser diode is emitted while the non-imaging type emits heat. Both types of sensors emit energy and are processed by a signal processor. Infrared sensors are also classified into active and passive.
The IR Sensor consists of an IR LED as an emitter and a photo-diode as the receiver. The IR light received by the sensor changes the resistance of the photo-diode. The intensity of this response determines the sensor’s output. It has a range of infrared wavelengths. This wide range allows for the sensor to detect objects even in low-light conditions.
What is IR sensor
IR sensor is an electronic device that emits light in order to sense some object of the surroundings. An IR sensor can measure the heat of an object as well as detects motion. Usually, in the infrared spectrum, all the objects radiate some form of thermal radiation. These types of radiations are invisible to our eyes, but infrared sensors can detect these radiations.
The producer is essentially an IR LED (Light Emitting Diode) and the indicator is basically an IR photodiode. The photodiode is sensitive to IR light of a similar frequency which is radiated by the IR LED. At the point when IR light falls on the photodiode, the protections and the yield voltages will change in relation to the extent of the IR light got.
There are five basic elements used in a typical infrared detection system: an infrared source, a transmission medium, an optical component, infrared detectors or receivers, and signal processing. Infrared lasers and Infrared LEDs of specific wavelengths are used as infrared sources.
The three main types of media used for infrared transmission are vacuum, atmosphere, and optical fibers. Optical components are used to focus the infrared radiation or to limit the spectral response.
Types of IR Sensor
There are two types of IR sensors are available and they are,
- Active Infrared Sensor
- Passive Infrared Sensor
Active Infrared Sensor
Active infrared sensors consist of two elements: an infrared source and an infrared detector. Infrared sources include the LED or infrared laser diode. Infrared detectors include photodiodes or phototransistors. The energy emitted by the infrared source is reflected by an object and falls on the infrared detector.
Passive IR sensors are basically Infrared detectors. Inactive infrared sensors do not use an infrared source and detector. They are of two types: quantum and thermal. Thermal infrared sensors use infrared energy as the source of heat. Thermocouples, pyroelectric detectors, and bolometers are the common types of thermal infrared detectors. Quantum-type infrared sensors offer higher detection performance. It is faster than thermal-type infrared detectors. The photosensitivity of quantum type detectors is wavelength-dependent. PIR Sensor full form is Passive IR Sensor.
IR Sensor Working Principle
There are different types of infrared transmitters depending on their wavelengths, output power, and response time. An IR sensor consists of an IR LED and an IR Photodiode, together they are called Photo Coupler or Opto Coupler.
IR Transmitter or IR LED
An infrared Transmitter is a light-emitting diode (LED) that emits infrared radiations called IR LED. Even though an IR LED looks like a normal LED, the radiation emitted by it is invisible to the human eye.
The picture of an Infrared LED is shown below.
IR Receiver or Photodiode
Infrared recipients or infrared sensors detect the radiation from an IR transmitter. IR recipients come as photodiodes and phototransistors. Infrared Photodiodes are not the same as would be expected photograph diodes as they distinguish just infrared radiation. The underneath picture shows the image of an IR recipient or a photodiode.
Different types of IR receivers exist based on the wavelength, voltage, package, etc. When used in an infrared transmitter-receiver combination because the wavelength of the receiver should match with the transmitter.
The emitter is an IR LED and the detector is an IR photodiode. The IR photodiode is sensitive to the IR light emitted by an IR LED. The photodiode’s resistance and output voltage change in proportion to the IR light received. This is the underlying working principle of the IR sensor.
When the IR transmitter emits radiation, it reaches the object and some of the radiation reflects back to the IR receiver. Based on the intensity of the reception by the IR receiver, the output of the sensor defines.
IR sensor Applications
IR sensors are used in various projects and also in various electronic devices. They all are as follow,
Night Vision Devices
Infrared technology is implemented in night vision equipment if there is not enough visible light available to see unaided. Night vision devices convert ambient photons of light into electrons and then amplify them using a chemical and electrical process before finally converting them back into visible light.
IR sensors use in radiation thermometers to measure the temperature depends upon the temperature and the material of the object and these thermometers have some of the following features
- Measurement without direct contact with the object
- Faster response
- Easy pattern measurements
An Infrared tracking or Infrared homing is a missile guidance system that operates using the infrared electromagnetic radiation emitted from a target to track it.
IR Imaging Devices
IR image device is one of the major applications of IR waves, primarily by virtue of its property that is not visible. It uses for thermal imagers, night vision devices, etc.
What is IR Sensor in mobile
The “IR” in IR blaster stands for “infrared.” The hardware itself is also equally simple to understand. If your phone has an IR blaster, it allows you to send commands via infrared rays to another device, such as a television, set-top box, or stereo compatible with IR remotes.
Other Key Application Areas
Other key application areas that use Infrared Sensors include:
- Gas detectors
- Moisture Analyzers
- Anesthesiology testing
- Petroleum exploration
- Rail safety
- Flame Monitors
- Gas Analyzers
- Water analysis
Hope this article helps you to understand about the working principle of IR sensor and its application. To know more about IR sensors.