Why is a spectral confocal sensor necessary for high precision measurement projects? With the rapid update of the appearance design of 3C products and the continuous upgrading of material technology, spectral confocal displacement sensors have been used more and more in the automated measurement of 3C products in the manufacturing process in recent years. The spectral confocal displacement sensor has its unique advantages in many measurement applications such as the back shell, middle frame segment difference, LOGO segment difference, camera segment difference, and 2D/3D screen surface profile. The Chinese automated measurement market defines the spectral confocal displacement sensor as a new type of sensor that can solve many difficult measurement applications with high accuracy.

The laser displacement sensor must be installed in two ways for diffuse reflection and specular reflection surfaces, and even two forms of probe cannot stably measure different reflective surfaces at the same time. The spectral confocal sensor does not need to be re-installed or adjusted for each material. For the measured object with a variety of materials, only one sensor can be used, one installation method can be stable measurement, and the junction of different materials can also be stable measurement. The spectral confocal displacement sensor has very high scanning accuracy and can measure roughness in accordance with ISO2587 international standard. Laser displacement sensor can not achieve roughness measurement, and Japanese and domestic spectral confocal sensors can not achieve roughness measurement because the spot is too large and the resolution is not enough. When measuring the difference between camera, lens and bracket, LOGO segment, high-end spectral confocal sensor must be used.

The LED light source emits a wide spectrum of polychromatic light (white), spectral dispersion occurs through the dispersion lens, and monochromatic light of different wavelengths is formed within the range. The focus of each wavelength corresponds to a distance value. The measured light is reflected back to the surface of the object, and only the monochromatic light that meets the confocal condition can be sensed by the spectrometer through the small hole. The distance value is obtained by calculating the wavelength of the sensed focus.

The Angle characteristics are greater

Angular characteristics refer to the maximum inclination Angle of the sample that can be measured. When the laser displacement sensor is measuring non-plane, the tilt or surface can not be accurately measured due to the difference caused by the return light. The sensor adopts the spectral confocal measurement technology to ensure that even if the measured object has too large tilt or surface, it can also measure the shape with high precision. The confocal displacement sensor probe for diffuse reflection surface can reach ±87°, and the confocal displacement sensor probe for specular reflection can basically reach more than ±20°. Most of the Japanese and domestic spectral confocal displacement sensors are not clearly marked because of the very low parameter. Poor angular characteristics can cause many irregular positions to be improperly measured. High-end spectral confocal sensors are required to measure non-planar surfaces, especially for 3D glass contours, dispensing glue heights, and high-gloss metal surface segment differences.

The measurement spot is smaller

Because the laser displacement sensor adopts the principle of triangulation and large light spot, there are many problems such as shape contour distortion, abnormal fluctuation of edge position and decrease of detection accuracy caused by multi-surface reflection when measuring section difference and gap. The use of spectral confocal measurement technology and the measurement spot can be measured up to 10μm, can measure a clear contour, and can ensure a very high measurement accuracy.

The surface of different materials can be stably measured

The laser displacement sensor must be installed in two ways for diffuse reflection and specular reflection surfaces, and even two forms of probe cannot stably measure different reflective surfaces at the same time. The spectral confocal sensor does not need to be re-installed or adjusted for each material. For the measured object with a variety of materials, only one sensor can be used, one installation method can be stable measurement, and the junction of different materials can also be stable measurement. The spectral confocal displacement sensor has very high scanning accuracy and can measure roughness in accordance with ISO2587 international standard. Laser displacement sensor can not achieve roughness measurement, and Japanese and domestic spectral confocal sensors can not achieve roughness measurement because the spot is too large and the resolution is not enough. When measuring the difference between camera, lens and bracket, LOGO segment, high-end spectral confocal sensor must be used.

Movable encoder synchronous hard trigger

Spectral confocal measurement technology because of its excellent resolution from the beginning of development is as a scanning measurement sensor, can achieve scanning measurement in motion, unlike the traditional laser displacement sensor can only do fixed point height measurement. Equipment manufacturers in China's automation industry have not yet fully realized full speed measurement in motion by triggering hardware I/O or reading encoder signals during motion. With its own encoder conversion and frequency division module, it can convert the encoder differential or single-ended signal into I/O to trigger the sensor, while solving the problems of low efficiency, poor stability and poor synchronization of traditional soft trigger measurement, so that customers can easily achieve measurement in motion.

Space and measurement area limitations can be resolved

The traditional laser displacement sensor uses the triangulation method to monitor the change of the position of the reflective spot on the sensor to measure the change of distance. Its biggest drawback is that the receiving end is not in the same position as the transmitting end, which is very susceptible to reflection interference from various surfaces in space. In use, it is necessary to perform harsh Angle tilt or direction rotation according to the real situation. The sensor is a confocal optical path with no direction limitation. Under the same installation conditions, the measurement can be carried out in all directions. High-end spectral confocal sensors must be used when measuring narrow areas such as blind holes and narrow cracks.

Do not use moving averages

The traditional laser displacement sensor needs to add 1024 times or even higher moving average when the data is displayed to solve the problem of measurement value pulsation induced by multiple reflections of the measured object, and measurement value fluctuation caused by the difference between the direction of the sensing head and the direction of the measurement line. Moving average will lead to deterioration of measurement accuracy and serious distortion of scanning shape. The stability of the spectral confocal technology is much higher than that of the traditional laser displacement sensor, and the spectral confocal displacement sensor adopts the non-moving average mode to display and output the measured value. Because of their poor stability, Japanese and domestic spectral confocal displacement sensors also need to add 1024 times or even higher moving average to make the measurement data stable. High-end spectral confocal sensors must be used to scan and identify real surface morphologies such as scratches and inflection points.

Strong technical support

Spectral confocal displacement sensor has a strong measuring ability, but it needs professionals to give the correct software and electrical design to achieve. Due to the inability of some sensor manufacturers to provide professional technical solutions and support, many automation equipment manufacturers have not fully developed the measuring capability of spectral confocal displacement sensors in many projects. There is no large number of pure sales personnel, more is can go to the customer site really understand the electrical knowledge can wire and adjust the engineer, can go to the customer site directly to the customer to write the program engineer.

Spectral confocal displacement sensor is mainly used in off-line high-precision measurement in some laboratories. With the continuous improvement of automated measurement requirements, spectral confocal displacement sensors are gradually applied to automated measurement equipment, at the beginning of 2014, European confocal displacement sensor manufacturers have not put the Chinese market in their eyes, they believe that the Chinese market only accounts for about 20% of its global market. Spectral confocal displacement sensors are more used in automated measurement of high value-added products such as automobiles and watches in Europe and the United States.