Vaisala INTERCAP^® Sensor

The Vaisala INTERCAP^® Sensor is the world's first interchangeable capacitive humidity sensor. If the sensor needs to be changed, the old sensor is replaced with a new one and measurement continues without any need for adjustment or calibration. This means great savings in both maintenance time and effort. The Vaisala INTERCAP^® based products are used for monitoring applications in normal ambient conditions.

The operating principle

The thin polymer film either absorbs or releases water vapor as the relative humidity of the ambient air rises or drops. The dielectric properties of the polymer film depend on the amount of water contained in it: as the relative humidity changes the dielectric properties of the film change and so the capacitance of the sensor changes. The electronics of the instrument measure the capacitance of the sensor and convert it into a humidity reading.