Does Adaptive PM2.5 Correction Transfer Across Devices, Sites, and Time? A Prospectively Frozen Three-Role PurpleAir Evaluation
IEEE ICOCO 2026 · Accepted with revisionLow-cost PurpleAir sensors need correction before their PM2.5 readings can be trusted, and adaptive corrections look excellent on the data they were fitted to. This paper asks whether that correction still holds on a new device, at a new site, and a year later. Using a prospectively frozen three-role protocol that fixes the model, the evaluation, and the held-out roles before any test data is seen, it measures transfer honestly and reports the negative findings alongside the positive ones.