In the fields of precision manufacturing and scientific research, the flatness of granite precision platforms is a key indicator to ensure the accuracy of equipment. The following is a detailed introduction to several mainstream detection methods and their operation procedures for you.
I. Laser interferometer Detection method
The laser interferometer is the preferred tool for high-precision flatness detection. Take the ZYGO GPI XP laser interferometer as an example, its resolution can reach 0.1nm. When conducting the detection, first align the light source of the interferometer with the platform and divide the platform surface into 50mm×50mm grid areas. Subsequently, the interference fringe data were collected point by point, and the data were fitted and analyzed using the Zernike polynomial to obtain the flatness error. This method is applicable to high-precision platforms and can detect flatness errors of ≤0.5μm/m². It is commonly used in the detection of photolithography machines and high-end three-coordinate measuring machine platforms.
Ii. Electronic Level Array Method
The electronic level array detection is simple to operate and highly efficient. The TESA A2 electronic level (with a resolution of 0.01μm/m) was selected and arranged in a 9×9 array along the X/Y axis direction of the platform. By synchronously collecting the inclination data of each level and then using the least square method for calculation, the flatness value can be accurately obtained. This method can effectively identify the local concavity and convexity conditions of the platform. For example, a fluctuation of 0.2μm within a 50mm range can also be detected, which is suitable for rapid detection in mass production.
Iii. Optical Flat crystal Method
The optical flat crystal method is suitable for the detection of small area platforms. Attach the optical flat crystal tightly to the surface to be tested on the platform and observe the interference fringes formed between them under the illumination of a monochromatic light source (such as a sodium lamp). If the stripes are parallel straight stripes, it indicates good flatness. If curved stripes appear, calculate the flatness error based on the degree of stripe curvature. Each curved stripe represents a height difference of 0.316μm, and the flatness data can be obtained through simple conversion.
Four. Three-coordinate Measuring machine Inspection method
The three-coordinate measuring machine can achieve high-precision measurement in three-dimensional space. Place the granite platform on the worktable of the measuring machine and use the probe to uniformly collect data from multiple measurement points on the surface of the platform. The measuring machine system processes and analyzes these data to generate a flatness report of the platform. This method can not only detect flatness, but also obtain other geometric parameters of the platform simultaneously, and is suitable for the comprehensive detection of large granite platforms.
Mastering these detection methods can help you accurately assess the flatness of the granite precision platform and provide a reliable guarantee for the stable operation of precision equipment.
Post time: May-29-2025