🔍 Key Concepts

• Recognize common precision measuring tools: feeler gauge, depth micrometer, vernier caliper, outside micrometer • Think about which tools are meant to measure clearances/gaps, which measure depth only, and which can measure diameters • Focus on which instrument has features (jaws or probes) that can contact both the inside and outside surfaces of an object

💭 Think About

• Look at the shapes of the measuring ends on each device. Which one clearly has one set of contacts for outside dimensions and a different set for inside dimensions? • Which tools are limited to a single direction of measurement (such as only thickness, only depth, or only external size)? • If you needed to measure both the outside diameter of a shaft and the inside diameter of a matching bushing, which single tool in the picture could reasonably do both jobs?

✅ Before You Answer

• Identify which device has two different types of jaws or contacts on the same scale • Confirm that the chosen tool is not restricted to just depth or just outside measurements • Make sure the tool you pick could realistically be used to check both inside diameter and outside diameter of cylindrical parts