SDS3909 is a dust particle counter based on the principle of single-particle laser scattering. It can accurately measure 8 common particle sizes in the industry, including 0.1μm, 0.15μm, 0.2μm, 0.25μm, 0.3μm, 0.5μm, 1.0μm, and 5.0μm. Through the standard RS485 interface and Modbus protocol, the data is transmitted to various intelligent terminals in real time.
As a new generation of ultrafine particle counter, SDS3909 has benefited from the rapid development of semiconductor industry technology in recent years. It has applied the latest generation of products in key components such as light source, detector, core processor, etc. It adopts high-power wide-temperature semiconductor laser, single-photon detector array and high-frequency 32-bit processor. The whole machine is designed and debugged according to ISO21501-4 standard. The equipment has accurate counting and good stability, and is a “true 0.1μm dust particle counter”.

Function characteristics
● Accurate data: single particle laser scattering principle, industrial-grade laser light source. High counting efficiency, good repeatability and consistency.
● Particle size range: Particle size range is 0.1~5 μm , ensuring counting efficiency while a single sensor covers eight channels.
● High reliability: Aerodynamically corrected optical and gas path self-checking, insensitive to vibration, ensuring system reliability and stability.
● Stable flow: It adopts active sampling method and is equipped with PID flow control function, which can support stable, long-term, high negative pressure and sampling; optional air pump version with external high-performance air pump module.
● Fast response: data is updated within seconds.
● Communication interface: RS485 and Ethernet output as standard.
● Sound and light alarm: Sound and light alarm function is standard, and the alarm value can be set.
● Circuit safety: With ESD, overvoltage, overcurrent, and reverse connection protection, it ensures the stability and reliability of the circuit.
● Easy installation: simple installation structure and high versatility.
● Safe and friendly: low voltage power supply, no electric shock; no radiation source, no light pollution.
● Sampling flow rate: standard 2.83L/min, two sampling modes: air pump/fan are optional.
Application scenarios
Technical parameter
| No. | Project | Parameter | Notes |
| 1 | Internet traffic | 2.83L/min | |
| 2 | Particle size range | 0.1μm、0.15μm、0.2μm、0.25μm、0.3μm、0.5μm、1.0μm、5.0μm | 8 channels |
| 3 | Protocol | Modbus-RTU/TCP | |
| 4 | Interface | RS485、Ethernet | |
| 5 | Screen | 5-inch touch screen | |
| 6 | Light source | Long life laser diode | |
| 7 | Maximum concentration | 1,000,000 pcs/ft3 | |
| 8 | Counting efficiency | 50%@0.1μm; 100%@Particle size>0.15μm | Conform to ISO 21501-4 |
| 9 | Calibration | ISO 21501-4、GB T29024.4-2017、JF 1190-2008 | |
| 10 | Work environment | Temperature: 10~40℃;Humidity: 20~95%RH(No condensation) | |
| 11 | Storage | Can store no less than 5 million pieces of data | |
| 12 | Power supply | DC12V [9-28VDC], power supply not less than 12V3A | |
| 13 | Power | fan ver: 17.5W; pump ver: 18.5W | |
| 14 | Size | 220.5*162*131mm | Excluding inlet and outlet sampling heads (fan version has no outlet) |