Optical systems baffling

Vermeulen et al. (V2) measured the interfacial surface produced in two-liquid batch systems in baffled vessels fitted with a flat-bladed paddle impeller, using an optical technique. The time required to reach a steady-state degree of dispersion ranged from less than 1 min. to as much as 2 hr. or more. Average drop diameters were in the range 0.003 to 0.1 cm. Drop diameters increase with the distance from the impeller in other words, coalescence occurred, especially for systems which reached steady state quickly. For two-liquid systems it was found that... 

To increase flexibility, mechanical baffles are being replaced more and more with optical parts-recognition systems in the vibratory bowl feeder. The geometry of the various workpieces can be programmed, stored in, and retrieved from the control system if there is a change of product. This means that retooling can be kept to a minimum. 

The rapid-water-quenching system produces good optical properties, has low equipment cost, but can be difficult to use to get precise control over the water temperature. Vibrations and currents can cause little marks on the film. A critical point is the necessity for maintaining a smooth surface in the water quench tank where the melt first enters. Different devices are used to control the flow of water such as baffles with openings. It has serious limitations when high production speeds are attempted the water must be kept from carrying over into any on-line pretreatment and the finished roll. However, these problems can be controlled. This liquid bath system has been used for blown tubular film inside the blown film to improve... 

Figure 1 shows in schematic detail an idealized reflective telescope for aerospace applications. The focal plane is a cryo-genically cooled series of photo-optical sensors operating below 100 K. The walls and baffles of the system also must operate in that temperature region to prevent their becoming extraneous inputs to the sensor system. The restraints this puts on the materials of construction and how these problems are met are the subject of this section. 

A Ge Ga photoconductive detector at lOOym and a GaAs epitaxial photoconductive detector at 285ym has been optimized for sensitivity comparison with a conventional bolometer system of Yerkes Observatory. The response of the photoconductive detectors were studied in the laboratory under two background conditions baffles and Fabry Optics. A direct comparison of the photoconductive detectors to the bolometer will be made on the 91.5 cm telescope aboard the NASA C-141 Airborne Infrared Observatory. 

As with infrared cameras, proper baffling and pupil stops are essential. Besides the dispersive element, the main difference in spectroscopic instruments is the requirement that the beam be well collimated when it encounters the disperser. Spectroscopic systems therefore generally have two main optical components. First there is a collimator that produces a collimated beam for the disperser and then a camera that focuses the dispersed light onto the detector array. 

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