Calibration

The life of the sensor element is primarily limited by drift of the humidity sensor and your own acceptance of the errors incurred. Typical drift is less than 1% per year when used in cleaner environments but can be higher in polluted air. Because it can be difficult to know what the sensor has been exposed to, and because the element is relatively inexpensive, Campbell Scientific recommends replacing the sensor element annually. Replacing the element effectively brings the sensor back to a factory calibration state both for temperature and relative humidity.

If you wish to check an old element’s calibration, you can measure its performance by plugging it into another sensor body in your calibration laboratory.