利用双光路补偿原理,测定同品种被测薄膜与参考薄膜的相对透过率差,得到被测膜厚。对若干品种薄膜进行了测定,精度已满足生产工艺的要求。 By using the principle of dual optical compensation, the relative transmittance difference between the tested film and the reference film of the same variety is measured to obtain the measured film thickness. A number of varieties of films were measured, the accuracy has to meet the requirements of the production process.