What is a Dust Sensor?

Dust sensor: image source Freepik

Dust is among the key air pollutants. It does more than just air pollution. It can cause serious damage when it gets into sensitive places. This is why some rooms are designed to be dust-proof, or dust-resistant. They are designed to prevent dust from getting in for one reason or another.

When it comes to deeper levels, dust sensors are deployed. These are used in super-sensitive applications where the performance and operation of a device can severely affect devices and objects.

 In this article, we are going to discuss everything that you should know about dust sensors. You will know how these sensors work and their importance in the world of electronics. If you are planning to embed the sensors into your application, you will learn various tips that will help you choose the best dust sensors.

Dust sensor working principle

Image source Research Gate

Dust sensors are simple but powerful electronic devices that are designed to sense dust. They have the full capacity to detect all types of dust, whether it is soil dust, pollen, smoke, house dust, or any other form of dust. As long as it is tiny particles whose size exceeds 1 micron, the sensor will detect or sense it.

But, how do these sensors work?

 Under normal circumstances, particles and even molecules tend to cause light to scatter whenever they are illuminated by an irradiation and beam of light. The same particles can absorb some energy from the irradiated l beam of light.

When a beam of light gets into any particular defined field of particle, it will be a key subject of scattering and absorption of energy. This will eventually increase the intensity of light. It is possible to measure the rate at which light energy is attenuated through the system.

The attenuation of light is a reflection of the level of dust particles in any particular field. Usually, the strength of light intensity is directly proportional to the rate of electric signal that is generated by the photoelectric conversion.

 In short dust sensors work on the principle of detection.  The presence of dust will scatter a defined beam of focused light. The rate at which light is scattered is measured and is used to determine the presence of dust in that area.

 The light source that is used for dust-sensing must be strong and well-defined. This makes it possible to provide accurate values about the presence of dust.  Infrared LEDs are used in most light sensors as the source of light. 

To work with the light source is a photodetector. This component is used for measuring the intensity of light that is generated by a light source. Take note that this detector measures the light intensity after the scattering that has been caused by the dust particles. It is strategically located in the detection chamber of a dust sensor from where it can capture all the scattered light rays.

 At the end of all these activities, signals with defined features and properties are generated. They are processed and interpreted by other electronic components. Depending on the application, the interpreted signal will trigger an action based on the level of dust that has been detected.

Components of dust sensors

From the above working principle, it is easy to pinpoint the key components and parts of dust sensors. The key components include signal processing IC, JST connector, transistor, enclosure, photodiode, lenses, and IR LED.

Each of these sensors has a specific role to play in the overall working of the sensor. For example, the signal processing IC is responsible for processing the signals. Transistors are used for amplifying signals before they are processed. This helps to improve the accuracy of the signals. 

Since a sensor derives power from a single source, a potentiometer is used as a voltage divider. It ensures that each component gets the right amount of power that it needs. Also, a potentiometer and a transistor are used for driving the LED. They determine the brightness of light that is radiated from the LED.

Infrared LED produces the light that drives the whole sensing functionality. The rays from the Infrared are powerful enough to trigger the dust-sensing operation. The main function of the lenses in a dust sensor is to focus the light beam toward a desired direction. The enclosure plays a protective role. It protects the whole setup from physical and mechanical damage.

Key features of dust sensors

Here are some of the key features that define dust sensors:

· Operate on PWM mode output: These sensors rely on the pulse width modulation to generate output signals. This means that they have rapid switching capabilities between active and inactive states, which determine the power that is directed to the load. This mode forms a square wave with two defined states: active and inactive.

· Single power supply:  A dust sensor is connected to a single power supply. This helps to generate defined signals that have uniform properties.

· Compact and simple design: These sensors are quite small and can easily fit into different electronic devices. The simplicity of these sensors also simplifies their installation process.

· Robust construction: Dust sensors are mechanically robust to ensure that they can operate effectively and also free from noise. Their robust feature also enhances their accuracy.

· Broad operating temperature range: The sensors are designed to operate at different temperature ranges.  The operating temperature of most dust sensors is between -20℃ and 80℃

What is the difference between an optical dust sensor and a laser dust sensor?

 While both are dust sensors, they use different technologies to operate. Laser dust sensors use laser technology, or laser diode to sense and detect dust. On the other hand, optical dust sensors use Infrared LED as the key driver in detecting dust.

 In terms of performance, laser dust sensors are always deemed to be more powerful and accurate than optical dust sensors.

Conclusion

Dust sensors are important in different applications. Some of these application areas include air conditioners, air quality monitors, air fresheners, air conditioning devices, air quality monitors, and many other applications in which the quality of air matters.

Are you planning to buy dust sensors for your device? Ensure that you get them from the right sources. We at ICRFQ can help you with this. We are a global supplier of dust sensors in China. Talk to us directly and we will deliver your order.