Which tool is typically used for measuring the internal diameter of a pipe?

• A. Dial indicator
• B. Caliper
• C. Micrometer
• D. Depth gauge

Answer: (B)

The use of a caliper is particularly suited for measuring the internal diameter of a pipe due to its design, which allows it to fit inside the pipe easily. Calipers come in various forms, such as vernier, digital, and sliding types, and they provide an accurate measurement by using two parallel jaws that can be adjusted to the desired width. In the case of internal measurements, there are specialized internal calipers that can extend into the pipe, ensuring precise readings.

While other tools can measure dimensions, they are not as effective for this specific task. For instance, a dial indicator is more commonly used for measuring small distances and variations in surfaces or for setting up equipment with precise alignment rather than measuring diameters. Similarly, a micrometer is typically used for measuring smaller items or dimensions with high accuracy but isn’t practical for larger diameters like those found in pipes. A depth gauge is mainly used for measuring the depth of holes or indentations and does not provide the necessary capability for internal diameter measurements.