Which measuring device is typically accurate within 0.001 in. (0.02 mm)?

A micrometer is a highly precise measuring device that is commonly used to measure small dimensions with a high degree of accuracy. It is typically accurate to within 0.001 inches (0.02 mm), making it ideal for tasks that require precise measurements, such as machining, metalworking, and quality control.

The design of a micrometer allows users to measure the thickness or diameter of an object with a screw mechanism, which translates small rotational movements into linear measurements. This feature is what provides the micrometer's superior accuracy compared to other measuring tools.

In contrast, while calipers can provide reasonably accurate measurements, they often have a larger tolerance and are generally less precise than a micrometer. Similarly, a Vernier scale is an auxiliary tool that typically provides measurements at a lower precision than that of a micrometer. A gauge is used for measuring specific dimensions or tolerances but is not typically designed for the precision achieved by micrometers. Thus, the micrometer stands out as the measuring device that meets the required accuracy threshold.