Ambient Weather Support

How Can I Test The Accuracy Of My Hygrometer (Humidity Calibration)?

    1. Place the sensor inside next to the indoor console sensor. Wait about 24 hours for stabilization. The sensors should agree within the accuracy specifications. Most digital capacitive hygrometer sensors are accurate within +/- 5%. Thus, the sensors should agree within 10% when considering full tolerance stack up.Note that humidity accuracy, like most other measurement parameters, are a percentage of full scale, and not a percentage of point.
    2. Sling psychrometers are very accurate. Perform a formal calibration. The humidity should agree within 5% of the  rating. You can also make your own calibration kit. For details, visit:

Testing The Accuracy Of A Hygrometer - Saturated Salt Test?

3.   Place the sensor in a shaded area on the north side of the structure to avoid direct and radiant heat.

4.  Humidity is significantly impacted by external factors like location and water (grass, lakes, rivers, etc). Insure proper installation. You cannot use a source like the National Weather Service. There are several reasons:

      • The NWS may update once per hour.
      • The NWS has strict installation guidelines (no unnatural structures, bodies of water, or unnatural vegetation nearby).

5.  If the problem persists, we have a one year warranty. Visit: