Which tool is commonly used for measuring the thickness of an aircraft structure?

The micrometer is the correct tool for measuring the thickness of an aircraft structure due to its precision and accuracy. Micrometers can measure small dimensions, often down to one-thousandth of an inch or even finer. This level of detail is critical in aircraft maintenance and structural integrity assessments, where tolerances are tight and material specifications are stringent.

The micrometer works by using a calibrated screw mechanism that allows for precise adjustments and measurements. Its ability to measure small changes in thickness makes it invaluable for tasks like checking sheet metal or structural components, ensuring they meet required specifications for safety and performance.

In contrast, while calipers, rulers, and gauges are useful for various measuring tasks, they do not offer the same level of precision as a micrometer. Calipers can measure outside dimensions, inside dimensions, and depths but typically lack the fine resolution needed for tasks requiring minute measurement increments. Rulers provide a broader measurement approach but are not suitable for precision work. Gauges are often specifically designed for certain applications, like identifying whether a feature meets a particular specification, but could be less versatile for general thickness measurements compared to a micrometer.