Humidity is always present in real applications of semiconductor gas sensors, e.g. in the environmental monitoring or medical applications, therefore it is important to study the effects that water vapor has on sensors conduction. This work is a study of the humidity role in the conduction mechanisms of two sensor materials: tin oxide (SnO₂) and a mixture of tin, titanium and niobium oxide (STN), showing the property of the second of being less affected by humidity, therefore useful in medical and environmental applications. Laboratory and on-field tests have been performed with water vapor and CO, at different concentration, initial conditions and partial pressures, both singularly and in combination. A novel concept of sensitivity is introduced in this work, called two-dimensional sensitivity, which not only quantifies the dependence of sensors response on the concentration of the analyte, but also on the variation of humidity and their non-linear combination. By taking the partial derivative of the fitting function with respect to CO concentration, it is possible to gather not only information about the dependence of the signal variation on the gas concentration, but also how it is influenced by water vapour, even when the water vapor partial pressure is kept constant, and vice versa.

在半导体气体传感器的实际应用中（例如在环境监测或医疗应用中）始终存在湿度，因此，研究水蒸气对传感器传导的影响非常重要。这项工作是研究湿度在两种传感器材料：氧化锡（SnO ₂）和锡，钛和铌的氧化物（STN）的混合物，显示出第二个特性不受湿度的影响，因此可用于医疗和环境应用。已经对水蒸气和一氧化碳进行了实验室和现场测试，这些水蒸气和一氧化碳的浓度，初始条件和分压分别不同或组合使用。在这项工作中引入了一种新颖的灵敏度概念，称为二维灵敏度，它不仅可以量化传感器响应对分析物浓度的依赖性，而且可以量化湿度及其非线性组合的变化。通过采用拟合函数相对于CO浓度的偏导数，不仅可以收集有关信号变化对气体浓度的依赖性的信息，