Hi Andualem, the most common method for validating PurpleAir data is by collocating PurpleAir sensors with regulatory monitors. Much research has been done using this method. I’ll provide a few examples:
- PurpleAir PM2.5 performance across the U.S.#2 | Science Inventory | US EPA
- AMT - An evaluation of the U.S. EPA's correction equation for PurpleAir sensor data in smoke, dust, and wintertime urban pollution events
- Correction and Accuracy of PurpleAir PM2.5 Measurements for Extreme Wildfire Smoke - PMC
- Pollutants | Free Full-Text | Long-Term Assessment of PurpleAir Low-Cost Sensor for PM2.5 in California, USA
Additionally, all outdoor PurpleAir sensors include two laser counters, which allow us to compare the data from the two channels and create a measure of confidence. You can learn more about it here: What are Channel A and Channel B?