光纤位移传感器在PET瓶胚壁厚测量中的应用研究

为了实现对聚对苯二甲酸乙二醇酯（PET）瓶胚壁厚实时、高效、高精度的测量，采用理论仿真结合实验验证的方法，以标称3.5mm厚型的PET瓶胚为例给出设计实例，建立了PET瓶胚壁厚测量的光学模型，根据光线追迹原理分析验证反射式光纤位移传感器在测量PET瓶胚壁厚中应用的可行性，并利用LIGHTTOOLS软件进行仿真模拟，最终设计出一种基于反射式光纤位移传感器对PET瓶胚壁厚实时测量的装置，并进行了实验验证。结果表明，实验装置的测量量程为3.20mm~3.80mm，线性度为15.8%，灵敏度为0.8448mV/μm，该装置相比传统测量效率提高了30%以上。这对提高实际检测效率和精度具有参考应用价值。

Study on application of optical fiber displacement sensor in measurement of PET bottle wall thickness

In order to realize real-time, high efficiency and high precision measurement of wall thickness of a polyethylene terephthalate (PET) bottle, through theoretical simulation and experimental verification, taking a PET bottle in 3.5mm thick as an example, the optical model for measuring the wall thickness of the PET bottle was set up. According to the principle of ray tracing, the feasibility of applying reflective fiber optic displacement sensor to measure the wall thickness of a PET bottle was proved. The simulation was carried out by LIGHTTOOLS software. Finally, a device based on reflective optical fiber displacement sensor to measure the wall thickness of PET bottle was designed and verified by experiment. The results show that, the measurement range is 3.20mm~3.80mm, the linearity is 15.8% and the sensitivity is 0.8448mV/μm. Compared with the traditional measurement method, the measurement efficiency of the experimental device will be increased more than 30%. The study has reference value for improving the efficiency and accuracy of actual detection.