Thermally detecting dew point sensors

Microtechnical solution for precise determination of moisture

The precise determination of humidity is very importance for many technical applications, particularly also in the range close to saturation. (85 to 100 % r.h.)

High relative humidities have a significant effect on corrosion processes, on structural damages and, by implication, on structural retention. High humidities must also be held constant in other areas, too, such as during the operation of incubators or measuring particles in the air, or be correctly compensated as a cross variable for measurements.

By contrast, other applications just require a »dew point monitor« that can detect the imminent condensation on a surface in advance to respond to it accordingly, e.g., with heating.

For all of these tasks, our thermally detecting dew point sensors are the ideal basis for an individual solution

Dew point distance and relative humidity

Our sensor chip primarily measures the dew point distance – the temperature difference to the ambient temperature at which condensation starts to set in. For applications, in which the relative humidity is sought, this can be easily calculated from the dew point and ambient temperature. Our sensor chip provides the two input variables. The temperature reduction of the sensitive chip surface, which is generated through an integrated Peltier structure, limits the measurement range. Currently this is approx. 10 K. Thus, humidity starting at approx. 65 % up to 100 % relative humidity can be precisely determined.

Essential advantages compared to the known polymer sensors for determining the relative humidity lie in the excellent resolution close to the saturation limit as well as in the high degree of robustness and a good chemical resistance of the sensor element.

At the Villingen-Schwenningen location, one of Hahn-Schickard's development areas are application-specific sensors and microsystems for measuring the dew point, dew point distance, and relative humidity. In close cooperation with our customers and partners, we offer R&D services for this purpose, from the initial idea up to the transfer to series production. On top of that, we also take on the manufacture of the microtechnology sensor element – the dew point sensor.

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