What tool is used for dimensional inspection of a bearing in a rocker arm?

The correct choice involves using both a telescopic gauge and a micrometer for dimensional inspection of a bearing in a rocker arm because this combination provides the precision necessary to measure the internal dimensions and overall geometry accurately.

A telescopic gauge allows for the measurement of internal diameters, particularly in tight spaces where other tools might not fit. It expands to fit the internal size of the bearing, allowing an accurate reading of its dimensions. This tool is particularly useful for getting into cavities or recessed areas in a rocker arm where bearings are seated.

Once the measurement is taken with the telescopic gauge, a micrometer is then used to measure the actual size of the gauge, providing a highly precise and accurate measurement of the bearing's dimensions. This process ensures that the bearings are within specifications, which is crucial for the proper functioning of the rocker arm assembly.

Using just a vernier caliper or a digital indicator may not provide the same level of precision required for internal measurements like those found in the context of a rocker arm bearing, and while a laser measurement system may be extremely accurate, it is often not practical for internal dimensions in this specific scenario. Therefore, combining the telescopic gauge with a micrometer is the optimal choice for this type of inspection.