Compared with traditional contact measurement methods, confocal sensors have obvious advantages such as speed, accuracy and adaptability. So what are the typical applications of spectral confocal sensors?

1. Application of surface roughness measurement

Surface roughness refers to the small gap formed on the machined surface of the workpiece due to factors such as different machining methods, machine and tool accuracy, vibration and wear during the machining process. and micro-level states of small peaks and valleys. It is an important measure of surface quality. Wear, sealing, lubrication, fatigue, research and other mechanical properties of associated parts.

Surface roughness measurement can be mainly divided into contact measurement and non-contact measurement. Contact contact measurement is easy to scratch the surface, the needle tip is easy to wear, the measurement efficiency is low, and it cannot measure complex surfaces. Non-contact measurement can achieve relatively non-contact, efficient, online real-time measurement, and become the development direction of roughness measurement in the future. At present, the commonly used non-contact methods mainly include interference method, scattering method, scattering method, concentration method and so on. Among them, the centralized method is relatively simple and practical.

A simple measuring device was constructed by using a spectral confocal displacement sensor to measure the roughness of the valve in the membrane gas meter through non-contact measurement to judge the tightness of the valve cover. Whether it is qualified or not, a certain effect has been achieved. Using a 2D nanometer measurement and positioning device based on a spectral confocal sensor, a non-contact measurement of the surface roughness of the roughness sample block was carried out. The measurement results were uncertain, and the U95 was 13.9%.

2. Application of contour and geometric dimension measurement

With the development of processing level, there are more and more small and complex workpieces that need contour measurement and precise dimension measurement, such as small round chamfer measurement, The inner wall groove size of small workpieces, etc. Some precision optical components also require non-contact profiling to prevent scratching the optical surface when measuring contact. These measurement problems, which are difficult to solve with traditional sensors, can be solved by building a measurement system using spectral confocal sensors.

3. Thin film material thickness measurement application

Spectral confocal sensor has unique advantages for precise measurement of material thickness due to the different wavelengths of monochromatic light reflected by different reflecting surfaces. Two reflective surfaces such as optical glass, biofilm, and parallel plates reflect monochromatic light of different wavelengths. Only one sensor is needed to estimate the thickness, and the measurement accuracy can reach the level of micrometers without damaging the surface to be measured. An application of measuring the thickness of transparent materials using a spectral confocal displacement sensor is introduced, and the measurement error range of the system is about 0.005 mm. The method of measuring the thickness of the parallel plate and the center of the optical lens by using the spectral confocal sensor is given, and the influence of the dispersion of the measuring object material on the thickness measurement accuracy is theoretically analyzed. In order to explore the relationship between the thickness of the film produced by the fluid falling method and the falling mode, Reynolds number, and tilt angle of the bottom plate, a spectral confocal sensor was used to monitor the thickness of the produced film in real time. Using the white light confocal sensor group installed on the top, the thickness and distribution of metal films with a thickness of 10 ~ 100  m are accurately measured, and the measurement uncertainty analysis is carried out, which shows that the measurement uncertainty of the system is about 0.12m.