在高精度面形检测中，绝对标定是提高检测精度的重要方法。但在平面绝对标定中，无论是经典的三平板绝对检测还是旋转平移绝对检测都无法对平面的power 项进行绝对标定。而利用液面进行绝对标定虽然可以给出完整的平面标定，但是液面易受环境影响，重复性难以提高，因此标定精度往往不高。针对这一难题，利用Fizeau 干涉仪，采用液面方法对平面的power 项单独进行绝对标定，结合旋转平移绝对标定方法对平面其他Zernike 项进行标定，从而得到了完整的高精度的平面绝对标定。不仅提高了检测精度，也对平面进行了完整的高精度标定，大大提高了干涉仪的检测精度。

Absolute calibration is an important method to improve accuracy in high precise surface figure testing. But for flat absolute calibration, the power of the flat cannot be calibrated in both the classic three-flat and the rotation- shifting absolute calibration. Using liquid surface absolute calibration can give flat surface figure including the power term, but the liquid surface is easily affected by environments and the repeatability is not good enough to get high accurate results. In order to solve the problem, liquid surface is used only to calibrate the power term and the other Zernike terms are calibrated by the rotation - shifting method. By this way, all the Zernike terms of the flat are absolutely calibrated and the test accuracy of the interferometer is greatly improved.