Procedure for connecting digital photo equipment to the testing machine control system
Journal Title: Вісник Тернопільського національного технічного університету - Year 2015, Vol 79, Issue 3
Abstract
Digital photography as a registration procedure is widely applied for conducting experiments, including the investigation of the fracture toughness characteristics of metallic materials. During photographing of the moving crack tip vicinity it is required to ensure the synchronization of photo numbers with the recording of the specimen loading parameters into the experiment file. To do this requires a digital or analog signal formed on the basis of a certain external physical process. This signal is related with photography and is available for recording and subsequent digitization of the testing machine by controller. A light pulse, which occurs in photoflash actuation and undergoes transformation with the help of photosynchronizer, or a command signal, which turns on the photoflash and is picked up from the central synchronizer adapter during photographing, can be used as such physical process. Depending on the configuration of the testing machine controller one can use various hardware moduli designed for connecting external devices. Use of some of these moduli requires an additional source of direct current or a model strain measuring bridge. For recording the obtained digital signal “Photo” in the course of testing one can use different algorithms of data sampling and accumulation provided by the controller manager programs. Specific features of application, advantages and disadvantages of processes of accumulation Timed Acquisition and Level Crossing Acquisition are considered.
Authors and Affiliations
Ihor Limansky, Roman Kravchuk
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