This morning two RH nodes were reading about 3% high after a 1.2" overnight rain; my field workflow is power-cycle, check for capillary moisture in the M12, wipe and reseat, then log a 10‑minute baseline against a calibrated Testo and re‑zero only if the delta stays constant — anything you’d add? I’m trying to standardize this so techs collect comparable data without dragging out a full calibration kit on every call.
I’d add a quick temperature sanity check: a 0.5–1.0°C T error can present as about 2–3% RH, so compare the node’s T to the Testo and correct that before deciding to re‑zero. @alee58 is right about the vent filter; if you can, bag the probe with a dry desiccant for 5 minutes — if RH snaps back, it’s moisture hysteresis, not drift. Do your nodes log T separately so you can spot T/RH divergence right after rain?