Wittelb WIN-SN-PM2.5/1/10-M Particulate Matter Sensor - Modbus RS485, 12-24V DC

This sensor uses the Modbus RTU protocol over an RS485 serial interface. To connect to a 5V Arduino or 3.3V Raspberry Pi, you will need an external RS485 to TTL/UART converter module (e.g., MAX485). Wire the sensor's RS485 A/B lines to the converter, then connect the converter's TX/RX to your microcontroller's serial pins. Use a Modbus library (like ModbusMaster for Arduino) to read the holding registers for PM1.0, PM2.5, and PM10 values.

The sensor requires a 12-24V DC power supply. The maximum operating current is 1000mA (1A), so your power adapter or supply must be capable of delivering at least 12W (12V * 1A) at the lower end of the voltage range. Ensure stable, clean DC power for optimal sensor performance and to avoid communication errors.

Yes, it can be used in sheltered outdoor applications. Its operating range is -10°C to 60°C and 0% to 80% relative humidity (non-condensing). For fully exposed outdoor use, it is recommended to install it in a protective, ventilated enclosure that shields it from direct rain and sunlight while allowing for adequate airflow for sampling.

The sensor's Modbus parameters (slave address, baud rate, parity, stop bits) are configurable via specific Modbus holding registers as defined in the product's datasheet. You need to send a Modbus write command to these registers using a Modbus master device or software tool before deployment to set your desired network configuration.

It uses a laser scattering (optical) principle. A fan draws air through a chamber where particles pass through a laser beam. A photodetector measures the scattered light, and an algorithm calculates mass concentration. The sensor is factory calibrated and is designed for long-term stability. Periodic verification against a reference instrument is recommended for critical applications, but routine user calibration is not typically required.