Understanding Machine Sensing in Manufacturing — Lesson 2

This lesson covers the concept of machine sensing in metal additive manufacturing, focusing on spatially integrated sensors and spatially resolved sensors. It delves into the working of pyrometers, infrared pyrometers, and the use of photodiodes in measuring radiation intensity. The lesson also explains the concept of saturation in temperature detectors and the importance of the MECVT factor in using IR pyrometers. It further discusses the types of pyrometers, such as two-colored and dual wavelength pyrometers, and their applications. The lesson also introduces the concept of spatially resolved sensors, including image sensors or cameras, and the types of sensors used in standard cameras, namely CCD and CMOS. It also covers the use of thermal and quantum detectors in infrared wavelength range. The lesson concludes with a discussion on data gathering levels and machine sensing architecture.

Video Highlights

00:22 - Understanding spatially integrated sensors and spatially resolved sensors
04:24 - Explanation of two-colored pyrometers and dual wavelength pyrometers
10:23 - Discussion on the use of thermal detectors and quantum detectors in infrared wavelength range
19:47 - Discussion on co-axial and off-axial machine sensing architectures
27:41 - Discussion on the use of thermal cameras in powder bed fusion process

Key Takeaways

- Spatially integrated sensors like pyrometers measure the radiance of an object and its temperature.
- Photodiodes convert incoming electromagnetic radiation into an electrical current signal, which is proportional to the radiation intensity.
- Two-colored and dual wavelength pyrometers are used for measuring temperature on hot surfaces.
- Spatially resolved sensors, such as image sensors or cameras, can be classified based on wavelength, range, type of detectors, and resolution space and time.
- CCD and CMOS are the types of sensors used in standard cameras.
- Thermal and quantum detectors are used in the infrared wavelength range.
- Data gathering levels and machine sensing architecture play a crucial role in metal additive manufacturing.