Videos

The eombination in a compact system of an infrared sensor and a laser as excitation source is called a photothermal camera. The surface heating is aehieved by the absorption of the focused beam of a laser. This localisation of the heating permits a three-dimensional heat diffusion in the sample to be examined. The infrared (IR) emission of the surface in the neighbourhood of the heating spot is measured by an infrared detector. A full surface inspection is possible through a video scanning of the excitation and detection spots on the piece to test (figure 1). 

Illustration 10 Wallthickness Measurement with Impulse-Video-Thermography... 

The large temperature difference of the remarkable borehole, opposite other boreholes and their environment is significant. This high temperature difference is a typical feature for a small wall thickness between borehole and blade surface. For technical reasons, precise eroding of the boreholes is difficult. Due to this, the remaining wallthickness between the boreholes and the blade surface has to be determined, in order to prevent an early failure, Siemens/Kwu developed a new method to determine the wallthickness with Impulse-Video-Thermography [5],... 

Carl V, Quantitative Wallthickness Measurement with Impulse-Video Thermography, 7 ECNDT Copenhagen, May 1998... 

The following parameters are established on the basis of the video signal of the radioscopic image ... 

Contrast Sensitivity S For this purpose a test piece is used whose least material thickness to be resolved in the video signal corresponds to the contrast sensitivity. The test piece can be a step/hole image quality indicator as per EN 462-2. 

An X-ray image of a test object is converted by a X-ray TV unit (4), and complete video-signal from it is supplied to specialized computer (5). For conversion of X-ray images series X-ray vidicons LI-444 and LI-473 can be used or experimental X-ray vidicons of the same dimensions with a Be input window [2] sensitive to soft X-radiation developed in Introscopy Institute. >. ... 

The zoom optics between the image intensifier and the video camera gives the freedom to magnify details of the image for more detailed inspection. 

The squares visible in figure 5 represent the position of hard particles at the moment of recording. Therefore the time distance between two video records is about 1,3 ms at a record rate of 750 Hz. With these data it is possible to calculate particle velocity. Figure 8 shows the particle movement in the molten bath caused by flow processes. The particles are captured at the contour of the molten bath and transported into the liquid phase. 

Shaw S L, Salmon E D and Quatrano R S 1995 Digital photography for the light microscope results with a gated, video-rate CCD camera and NIFI-image software BioTechniques 19 946-55... 

Particles can be manipulated in suspension using strongly focused laser beams ( optical tweezers ) [25] or magnetic fields [26] and by collecting statistics on tire particle movements using video microscopy, infonnation on the particle interactions can be obtained. 

A typical layout controlled by the central microprocessor (CPU). Electrical inputs are received from the keyboard, mouse, or instrument. Outputs go to the video screen, printer, and the instrument. Memory and software are utilized hy the CPU on command. 

The input could be from a PC (personal computer), as in word processing, but could equally well be from an instrument the output could be to a video screen, a printer, or to the same or another instrument (Figure 42.9). All these functions are organized by the central processor in so-called real time, i.e., virtually immediately. 

Laser sensors Laser spray Laser surgery Laser video disks LaserVision Laser welding... 

Video links Video recording Video sensor Video tape Video tapes Vidicon Vidicons Vidicon tubes Vifilcon-A... 

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