Carbon dioxide (CO₂) sensor has a wide range of applications in many industrial fields. However, most existing CO₂ sensors exhibit obvious cross-sensitivity to environmental relative humidity (RH). Therefore, it becomes critical for CO₂ sensors to eliminate the interference of humidity. In this study, based on the advantages of conveniently constructing sensing network and multiplexing capability of FBGs, the combination of polyimide-coated fiber Bragg gratings (FBGs) and etched FBGs sensors with different sensitivities was proposed to detect the concentration of CO₂ and humidity levels simultaneously. Two sets of sensors were fabricated by changing the coating thickness and etching the grating region, respectively. The experimental results indicate that all the sensors have a good linear response to CO₂ and humidity, as well as excellent response reversibility and repeatability. The highest sensitivity of the sensors towards CO₂ was 0.585 με/vol% CO₂, while 4.191 με/% RH towards humidity. The CO₂+RH mixture exposure experiments were carried out to demonstrate the feasibility of simultaneous detection of CO₂ and humidity levels, which showed small deviations between the detected and set values of CO₂ concentrations and humidity levels. Moreover, the fabricated sensors can operate over a wide range of temperatures.

二氧化碳（CO ₂）传感器在许多工业领域都有广泛的应用。然而，大多数现有的 CO ₂传感器对环境相对湿度 (RH) 表现出明显的交叉敏感性。_{因此，CO 2}传感器消除湿度的干扰变得至关重要。本研究基于FBGs易于构建传感网络和复用能力的优势，提出了将聚酰亚胺涂层光纤布拉格光栅（FBGs）与不同灵敏度的蚀刻FBGs传感器相结合来检测CO _{2浓度的方法。}和湿度水平。分别通过改变涂层厚度和蚀刻光栅区域来制造两组传感器。实验结果表明，所有传感器对CO ₂和湿度均具有良好的线性响应，以及良好的响应可逆性和重复性。传感器对 CO ₂的最高灵敏度为 0.585 με/vol% CO ₂，​​而对湿度的最高灵敏度为 4.191 με/% RH。进行了CO ₂ +RH 混合物暴露实验以证明同时检测 CO ₂和湿度水平的可行性，结果表明 CO _{2的检测值和设定值之间的偏差很小}浓度和湿度水平。此外，制造的传感器可以在很宽的温度范围内工作。