A new method and device for the selective measurement of humidity at high temperature is presented. It consists of a TiO₂ sensor element and a Fourier-based impedance spectrometry (FobIS) device with a dynamic range from 100 Hz to 100 kHz. For selective humidity detection we use an electrical equivalent circuit model presented earlier [1]. In this model, the humidity can be attributed to a constant phase element describing the ionic conduction of humidity related species. In this work, we can demonstrate that humidity can be quantified at 320 °C in the range from 80 - 450 mbar with an accuracy of 12 mbar with this approach. Furthermore, we can show that the circuit element for ionic conduction is not dependent on reducing gas tested with 1000 ppm ethanol. The response to ethanol, however, contributes to an ohmic resistor describing the electronic conductance within the TiO₂. With compensation of reducing gas, humidity can be quantified with an error of 13 mbar.

提出了一种选择性测量高温湿度的新方法和装置。它由TiO _2组成传感器元件和动态范围从100 Hz到100 kHz的基于傅立叶的阻抗谱（FobIS）设备。对于选择性湿度检测，我们使用了较早提出的等效电路模型[1]。在此模型中，湿度可归因于描述湿度相关物质的离子传导的恒定相元素。在这项工作中，我们可以证明采用这种方法可以在320°C的温度范围内（80-450 mbar）对湿度进行定量，精度为12 mbar。此外，我们可以证明，用于离子传导的电路元件不依赖于用1000 ppm乙醇测试的还原气体。然而，对乙醇的响应有助于形成描述TiO ₂内电子电导的欧姆电阻。通过补偿还原性气体，可以量化湿度，误差为13 mbar。