“measles chart” in new reliability technique

A schematic diagram, called a “measles” chart has proved to be a reliable tool for locating, diagnosing, and correcting elusive troubles in circuits and components. The chart is marked with a dot near the schematic symbol of a failed part. The measles are colored dots on a diagram; they indicate true failures, handling failures, and test errors. With the chart, engineers of design and of reliability, shop-follow engineers, and field service engineers can analyze troublesome circuits and determine causes of failures. The charts aid in design of new circuits and act as a check on circuit reliability.