With diode-based sensors, a photodiode is used to measure the light emitted by the process. Not only the visible light but also the thermal emissions and the reflected radiation from the laser are of particular of interest. Therefore, the sensor must be capable of measuring optical radiation of different wavelengths with a very high resolution while reducing noise as possible. The processing, evaluation and correlation of the measured data is taken over by the plasmo software using algorithms specifically designed for this purpose. As soon as the processing procedure has been completed, the result is visualized and transmitted to the customer without any delay or increase to cycle time.
This is one of the huge advantages of “online process monitoring” compared to other technologies.
There are several possibilities for how the optical radiation can be transmitted from the process to the sensor. Currently an optical fiber is used for most of the application. In the future the new compact design makes it possible to connect the sensor directly to the C-mount adapter of a scanner optic. Basically, there are three options available. With the so-called “off-axis” integration, the process is observed from a sideways perspective. The second possibility is to observe the process via a camera adapter, “on-axis” and the third option is the direct integration into the process laser. (Illustration 1).
Manufacturers of process optics offer possibilities to directly integrate the plasmo sensor in their products. More information ... www.plasmo-us.com