All of our industrial COSA XENTAUR™ dew point meters use our Hyper Thin-Film (HTF™) Al2O3 Moisture Sensing Technology high capacitance sensors. Our Hyper-Thin-Film Technology is based on major advances in thin-film technology and metal oxide sciences. It provides measurements with a sensitivity several orders of magnitude larger than of those made with all other technologies. HTF sensors are free of drift and insensitive to temperature changes over most of their range.
The HTF Technology and all other aluminum oxide sensors share the same basic operating principle: the capacitance measured between the sensor’s aluminum core and a gold film deposited on top of the oxide layer varies with the water vapor content in the pores of the oxide layer. Three fundamental structural improvements in the oxide layer give our HTF sensors much increased sensitivity and stability: HTF sensors have much thinner oxide layer, a better-defined barrier layer between the aluminum and the aluminum oxide and a unique pore geometry enhancing the entrapment of water molecules.
With our HTF Technology, sensors can be produced with hyper-thin oxide layers without compromising insulation strength. The thinner oxide layer of HTF sensors results in much higher capacitance changes because capacitance is inversely proportional to the distance of the capacitor’s plates from each other. The thinner layer also means that water molecules will travel faster in and out of the pores. HTF aluminum oxide sensors therefore respond several times faster than conventional sensors.