The principle of capacitive dew point meters (polymer).

Principle of the High Response Speed Dew Point Meter TE-660 Series

The sensor uses a polymer material. The principle is the same as that of aluminum oxide sensors. The polymer-based capacitive sensor is a capacitor that has a dielectric layer that reacts to moisture in the surrounding gas. This dielectric layer ideally absorbs moisture in the same ratio as the surrounding moisture content, allowing it to detect the moisture level. Its advantages include fast response speed and long-term stability. However, measurements in low dew point areas below -50 °C dp have lower sensitivity compared to aluminum oxide types, so it outputs calculated values that combine actual measurements and predictions. Therefore, without an automatic calibration function, it cannot maintain accuracy. It has an automatic calibration function that corrects the zero point through heating, maintaining accuracy. The measurement range is from -60 °C dp to +100 °C dp. For more details on the principle of the capacitive dew point meter (polymer), please refer to the URL below.

Other temperature and humidity measuring instruments