Dust Smoke Particle Sensor An infrared emitting diode (IRED) and a phototransistor are diagonally arranged into this device. It detects the reflected light of dust in the air. Especially, it is effective to detect very fine particle like the cigarette smoke. In addition, it can distinguish smoke from house dust by the pulse pattern of the output voltage.

Tutorial:

https://www.hackster.io/infoelectorials/review-004-grove-dust-sensor-ppd42ns-review-a22b29

Main features:

• - Power supply voltage: DC5±0.5V
• -Working current: 90mA
• - Sensitivity: 0.5V/ (0.1mg/m3)
• - Minimum particle detection value: 1 microns
• - Output mode: pulse output  Hi 4V Lo 0.7V
• - Working temperature: -0~45°C
• - Working humidity: 0~95%RH
• - Size: 59mm * 45mm * 22mm
• Main features:
•  PWM way output;
• Compact structure, 
• light weight; 
• Easy to install; 
• Single power supply; 
• The price is low.

Main application:

• 1. air purifier and air cleaner;
• 2. air conditioning;
• 3. air quality monitor;
• 4. air conditioning and other related products.
• Main parameters:
• 1. optical principle, can detect more than 1 microns dust particles;
• 2. two kinds of output mode, to solve the different sensitivity of the use of the requirements, clean environment Vout output high level signal (4V);
• 3. 5VDC power supply;
• 4. the detect particle range: maximum to 8000pcs/283ml (above 1um above particle)