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Ecowitt WH41B

General Description

The Ecowitt sensors (Model: WH41B) are designed to provide real-time measurements of PM2.5 mass concentrations. It also measures temperature and relative humidity.

Principle of Operation

The Ecowitt sensors use Honeywell HPM Series Particulate Sensor which detects and counts particles using light scattering. The light scattered by the particles as they pass through the laser beam is recorded on the light detector. The light is then analyzed and converted to an electrical signal to calculate particle concentration. The detection concentration range of the sensor is 0 – 1,000 µg/m3.


  • Dimensions: 4 (L) x 2.8 (W) x 2.7 (H) in
  • Weight: < 1 lb
  • Battery: yes
  • Power supply: Yes (USB power cable)
  • Sensor lifetime: 10 years for the Honeywell HPM Series PM2.5 sensor
  • Clock function: no
  • Sampling mechanism: Fan
  • Environmental operating conditions: N/A
  • Internal data logging: No
  • Data communication and logging: WiFi, data can be retrieved via
  • Weatherproof: No


  • Indoor Air Quality
  • Outdoor Air Quality


Developer's Product Webpage – PM2.5 Sensor

    South Coast Air Quality Management District

    21865 Copley Dr, Diamond Bar, CA 91765



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