DSM501B Dust Sensor Module – High Accuracy PM2.5/PM10 Air Quality Detector for Arduino, HVAC, Air Purifier

Description

The DSM501B is a compact optical particle/dust sensor module from SamYoung, designed for indoor air quality monitoring in air purifiers, HVAC systems, ventilation equipment, and DIY electronics projects. It detects particles as small as approximately 1µm, including cigarette smoke, house dust, pollen, mites, and mold spores . Unlike analog-output dust sensors, the DSM501B provides PWM (Pulse Width Modulation) output: each output pin remains HIGH in clean air and pulses LOW when particles are detected. The low-pulse ratio (total low time divided by the measurement interval) corresponds to particle concentration, allowing a microcontroller to calculate dust density without an ADC .

The module features an internal heater that generates upward airflow, drawing ambient air into the optical detection chamber where an IR LED and photodetector measure scattered light . It offers two PWM outputs: Vout2 is factory-calibrated for particles over 1µm, while Vout1 has lower sensitivity (about 2.5× duller) and can be adjusted via a resistor on the Control pin to change the minimum detectable particle size from 2.5µm down to 1µm . The DSM501B uses a 2.5mm pitch JST EH connector (distinguishing it from the DSM501A with 2mm pitch) .

Important accuracy note: The DSM501B provides relative dust trend data, not laboratory-grade PM2.5 measurement. It is best suited for threshold-based control (e.g., fan speed adjustment) and qualitative monitoring. Calibration against a reference instrument is required for quantitative applications.

Features

• Dual PWM Outputs: Vout2 factory-calibrated for particles >1µm; Vout1 adjustable via Control pin resistor for particle sizes from 2.5µm down to 1µm .

• Internal Heater for Airflow: Generates updraft to draw ambient air into the optical chamber without an external fan .

• Detects Particles ≥1µm: Effective for cigarette smoke, house dust, pollen, mite, germ, and mildew .

• Simple PWM Interface: Low-pulse ratio readable by any digital GPIO; no ADC required .

• Compact and Lightweight: 59×45×20mm, approximately 25g .

• 5V Single Supply: Operates from 4.5V to 5.5V with 90mA current consumption .

• 2.5mm JST EH Connector (DSM501B): Distinguishes from DSM501A (2mm pitch) .

• Wide Operating Conditions: Functions from -10°C to +65°C and up to 95% RH (non-condensing) .

Technical Specifications