A __ is used with a micrometer to measure the inside diameter of small holes such as a valve guide in a cylinder head.
a) Telescopic gauge
b) Vernier dial caliper
c) Dial bore gauge
d) Feeler gauge
The Correct Answer and Explanation is :
The correct answer is c) Dial bore gauge.
Explanation
A dial bore gauge is an essential tool used in precision engineering and mechanical applications for measuring the inside diameter of cylindrical features, such as holes and bores. This tool is particularly useful for measuring the inside diameter of small holes, such as valve guides in a cylinder head, where accuracy is critical.
The dial bore gauge typically consists of a dial indicator mounted on a set of precision rods that can be adjusted to fit inside the bore being measured. The gauge is designed to provide a direct reading of the diameter on the dial face, allowing for quick and easy measurement.
To use a dial bore gauge, the operator first calibrates the tool to ensure accuracy. The gauge is then inserted into the hole or bore to be measured. The gauge’s arms expand to contact the inner walls of the bore. As the gauge is moved, the dial indicator shows the diameter of the hole at various points, helping to identify any inconsistencies or wear.
This tool is invaluable for assessing the condition of machined components, as it allows technicians to detect wear, out-of-round conditions, and other defects that can impact performance. In high-performance applications, such as engine building or repair, precise measurements of bore dimensions are critical for ensuring proper fit and function of components like pistons and valves.
In contrast, other measuring tools mentioned in the options serve different purposes. For example, a telescopic gauge is primarily used for measuring external dimensions, a Vernier dial caliper measures both internal and external dimensions but is less precise for small holes, and a feeler gauge is used for measuring gaps or clearances rather than diameters.
Overall, the dial bore gauge stands out as the best choice for measuring the inside diameter of small holes due to its accuracy, ease of use, and suitability for precision applications.