🔍 Key Concepts

• Purpose of a crankshaft deflection test on large marine diesel engines • Difference between tools that measure linear clearance versus bending/deflection • How deflection is usually read (scale, dial, or electronic sensor) between crank webs

💭 Think About

• Think about what exactly you are trying to detect when checking a crankshaft—are you measuring how much it is bent, or a small gap/clearance between two solid surfaces? • Which of these tools is commonly mounted between crank webs or structural points to see a change as the crankshaft is rotated? • Which options are generally used in machine shop work for precision sizing of parts, rather than for monitoring bending under load?

✅ Before You Answer

• Identify which option is specifically designed to detect strain or deflection rather than simple distance/clearance. • Eliminate tools that are normally used for measuring thickness or external dimensions (like diameter, length, or gap). • Ask yourself which device can be fixed in place and will change its reading as the shaft flexes while being rotated.