3951 4.3 Relative Displacement:Translational and Rotational XI.Photographic and Electronic-Imaging Techniques Application of still and motion-picture photography for qualitative and quantitative analysis of complex motions Single-flash "stop-action"can "freeze"a motion at a particular phase of its occurrence to allow detailed visual study of some physical phenomenon. Multiple-flash still camera technique can be used to record displacement with time information. High-speed motion picture photography is used to study motions that occur too rapidly for the eye to analyze properly. Charge-Coupled Device(CCD)camera for higher resolution and speed CMOS image sensors offer even higher speed with other advantages. 40/51 4.3 Relative Displacement:Translational and Rotational Ⅻl.Photoelastic(光弹性)，Brittle-Coating脆性涂层)，and Moir Fringe莫尔 条纹Stress-Analysis Techniques For small displacement measurement XIl.Displacement-to-Pressure(Nozzle-Flapper[喷嘴挡板])Transducer Widely used in precision gaging equipment and as a basic component of pneumatic(风动的)and hydraulic(液压的，水力的)measurement and control apparatus. XIV.Digital Displacement Transducers(Translational and Rotary Encoders) Native digital transducer for translational and rotational displacement measurement XV.Ultrasonic Transducers Use wave-propagation principle for displacement measurement4.3 Relative Displacement: Translational and Rotational XI. Photographic and Electronic-Imaging Techniques ‹ Application of still and motion-picture photography for qualitative and quantitative analysis of complex motions ‹ Single-flash “stop-action” can “freeze” a motion at a particular phase of its occurrence to allow detailed visual study of some physical phenomenon. ‹ Multiple-flash still camera technique can be used to record displacement with time information. ‹ High-speed motion picture photography is used to study motions that occur too rapidly for the eye to analyze properly. ‹ Charge-Coupled Device (CCD) camera for higher resolution and speed ‹ CMOS image sensors offer even higher speed with other advantages. 39/51 4.3 Relative Displacement: Translational and Rotational XII. Photoelastic(光弹性), Brittle-Coating(脆性涂层), and Moir Fringe(莫尔 条纹)Stress-Analysis Techniques ‹ For small displacement measurement XIII. Displacement-to-Pressure (Nozzle-Flapper[喷嘴挡板]) Transducer ‹ Widely used in precision gaging equipment and as a basic component of pneumatic(风动的) and hydraulic (液压的，水力的) measurement and control apparatus. XIV. Digital Displacement Transducers (Translational and Rotary Encoders) ‹ Native digital transducer for translational and rotational displacement measurement XV. Ultrasonic Transducers ‹ Use wave-propagation principle for displacement measurement 40/51