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11. Inspection Technologies 11.1 Unit Introduction 11.2 Unit Objectives 11.3 Contact vs. Non-contact Inspection Techniques 11.4 Conventional Measuring and Gauging Techniques 11.5 Co-ordinate Measuring Machines 11.6 Machine Vision 11.7 Other Optical Inspection Techniques 11.8 Non-contact Non-optical Inspection Technologies 11.9 Unit Review 11.10 Self Assessment 11.11 Self Assessment Answers 11.1 Introduction Inspection is the means by which poor quality is detected and good quality is assured in products that are produced in a production process. Inspection is usually carried-out manually via the use of various technologies that examine specific variables (quality characteristics of the product), or product attributes (to ensure product conformance to previously-set standards). The major steps in inspection include: BULLETLIST Presentation of the item for inspection Examination of the item for non-conformance on certain product attributes Decision-making, based on the results of the examination, whether the item passes the quality standards required, and assigning the product to a quality grade Action, based upon the decision reached, such as accepting or rejecting the item ENDLIST KEYPOINT Inspection is the process of presenting, examining, deciding-upon, and actingupon an item to ensure that poor quality is detected in product attributes, and good quality is assured. END KEYPOINT Various technologies support the inspection procedure, enabled by various sensors, instruments, and gauges. Some inspection techniques use manuallyoperated devices such as micrometers, callipers, protractors, and go/no-go gauges; whilst other techniques are based upon modern technologies such as co-ordinating measuring machines (CMM) and machine vision, which use computer-controlled systems that allow the inspection procedure to be automated. This unit focuses on automated inspection techniques. Some general characteristics of measuring instruments, used in the inspection procedure, may