|
所在平台: Udemy |
课程主页: https://www.udemy.com/course/visual-testing-non-destructive-testing-level-ii/
课程评论：没有评论
课程名称：视觉测试 - NDT II级 课程概述：视觉测试是最广泛使用的无损检测方法之一，几乎在所有行业中都用于识别零件中的缺陷和不连续性。视觉测试要求良好的视力，可以是自然视力或经过矫正的视力。通过镜子、放大镜、内窥镜等各种视觉辅助工具，可以增强缺陷或不连续性。通常，视觉检查的距离为约10至24英寸。视觉测试的光照要求最低为150 Lux，随着不连续性严重性的增加，光照强度也需增加。一般的家庭照明要求在200-250 Lux之间，适合正常视力，且 lighter objects与深色背景的最小对比度为3:1。 视觉测试的优点： - 视觉测试比其他测试方法成本更低。 - 在不同场所进行视觉检查非常方便，因此是非常便携的方法。 - 检查结果是即时的，使得视觉检查成为最快的无损检测方法之一。 - 进行视觉检查只需中等技能。 - 零件或样本的准备工作较少，即可进行检查。 视觉测试的缺点： - 视觉检查只能查看表面缺陷。 - 微小缺陷无法用裸眼观察到。 - 可能会在相关指示和非相关指示之间产生混淆。 本课程将深入探讨视觉测试的原理、优缺点以及在不同应用中的重要性。
Visual Testing is one of the most widely used nondestructive testing methods and is used in almost all industries to identify defects and discontinuities in part. For visual testing, good eyesight is required either natural or corrected. Defects or discontinuities are enhanced by mirrors, magnifiers, Borescope, and other various visual aids.Visual examination is performed usually at a distance of approximately 10" to 24". The light requirement for Visual testing Inspection is a minimum of 150 Lux and it increases as the seriousness of discontinuities increases. In general residential light, the requirement is of 200-250 lux for normal vision and minimum contrast of 3:1 for lighter objects and dark background.Advantages of Visual Testing-· Visual testing is less expensive than other testing methods.· It is very convenient to perform a visual inspection at a different place, hence it is a very portable method.· After inspection results of inspection is immediate and this makes visual inspection as one of the fastest NDT inspection methods.· Moderate skill is required for visual inspection.· Workpiece or specimen can be inspected with less part preparation also.Disadvantages of Visual Testing-· Only surface defects can be viewed by visual inspection.· Micro or small defects are not visible to unaided eyes.· Confusion occurs between relevant indication and non-relevant indications.
