Check your humidity sensors
PSA: identical smart home humidity sensors can differ by up to 5% — testers are urged to calibrate and cross‑check sensors before relying on automation or HVAC triggers sensor PSA.
How-To-Geek’s guide (published Mar 15, 2026) spells out a DIY saturated‑salt check that produces about 75% relative humidity at room temperature and recommends sealing sensors with a salt slurry for roughly 8–12 hours to let readings stabilize. howtogeek.com Premium consumer products publish tighter tolerances: SensorPush lists a typical accuracy of ±2%RH for its HT.w sensor, while Govee models commonly advertise around ±3%RH in their product specs and manuals. sensorpush.com Lower‑end modules and hobbyist chips often behave closer to ±5% in real tests—bench measurements of DHT‑series sensors show performance within the ±5% range, and weather‑station vendors note most electronic hygrometers are typically ±3–5% RH. youtube.com Automation platforms and apps support software offsets and template sensors for correction; Home Assistant community threads document users cross‑checking multiple devices and applying per‑sensor offsets, and Govee’s manual includes an in‑app calibration option. community.home-assistant.io For traceable accuracy, factory or lab calibration is available: Honeywell offers NIST‑traceable humidity calibrations at 2%, 3% and 5% points, and Fluke documents mixed‑flow and chilled‑mirror reference methods used in professional humidity calibration labs. controlscentral.com Practical protocols in the field include testing several sensors side‑by‑side to pick the most consistent units, placing the best‑performing sensors in high‑risk zones (basements, bathrooms), and scheduling periodic verification — many vendors advise at least annual checks if the readings are relied upon for controls. howtogeek.com
