基于红外双光路的薄膜在线测厚系统的研究

摘要

Infrared thickness measurement is one of the main methods of online film thickness measurement , but traditional infrared thickness measurement method still has such defects that it is sensitive to the stability of light source and it is not applicable to high-speed film production line .In order to solve these problems , a dual-light path reference measurement method was used and a dual-light path infrared thickness measurement system was presented .In the system, the light source is divided into measurement light path and reference light path , using a single CCD connecting both the measurement light and the reference light as light intensity sensor . The imaging principle was described and the applicability of the system for Lambert law was discussed . Finally, calibration experiments for polyethylene and polytetrafluoroethylene film were conducted to demonstrate the accuracy .The experimental results show that the method has high precision and good robustness , and can effectively avoid the impact of the unstable of light source .%红外测厚是薄膜在线测厚的主要方法之一，为了解决传统的红外测厚方法中尚存在的易受光源稳定性的影响、不适用于高速薄膜生产线等缺点，采用双光路参比测量的方法设计了一种双光路红外测厚系统，系统将光源的光分成测量路和参考路两路，并使用单个CCD同时收集两路光作为光强传感器。描述了系统的成像原理，讨论了系统对朗伯定律的适用性，最后通过对聚乙烯和聚四氟乙烯薄膜的标定实验论证了系统的精度。结果表明，该方法精度高、鲁棒性好，且能够有效避免光源不稳定带来的影响。