Answer :
Sure! When measuring hub runout with a dial indicator, you're measuring how much the hub deviates from being perfectly round or straight as it rotates. Let's look at the options:
- Option a: "The sweep of the needle on the gauge as the hub is rotated." This means you place the indicator on a fixed point and rotate the hub to see how much the needle moves. This directly measures the runout as you observe the maximum deviation during a full rotation, which is a common and accurate method for assessing runout.
- Option b: "The average of four measurements around the hub." This implies you measure at several points and then average the measurements. While this might provide useful information, it’s not typically the primary way to define runout, which is more about the maximum deviation.
- Option c: "The sweep of the needle on the gauge as the hub is moved inboard and outboard." This suggests measuring how much the needle moves when the hub is shifted sideways, which would indicate wobble rather than runout.
- Option d: "The average distance from the center of the hub to the ground as the hub is rotated." This isn't directly related to measuring runout, as runout typically refers to deviations from roundness or straightness rather than measuring distance to the ground.
Based on these interpretations, Option a is the correct answer. It accurately describes using the dial indicator to measure the variations (or the sweep) as you rotate the hub, which is the essence of runout measurement.
- Option a: "The sweep of the needle on the gauge as the hub is rotated." This means you place the indicator on a fixed point and rotate the hub to see how much the needle moves. This directly measures the runout as you observe the maximum deviation during a full rotation, which is a common and accurate method for assessing runout.
- Option b: "The average of four measurements around the hub." This implies you measure at several points and then average the measurements. While this might provide useful information, it’s not typically the primary way to define runout, which is more about the maximum deviation.
- Option c: "The sweep of the needle on the gauge as the hub is moved inboard and outboard." This suggests measuring how much the needle moves when the hub is shifted sideways, which would indicate wobble rather than runout.
- Option d: "The average distance from the center of the hub to the ground as the hub is rotated." This isn't directly related to measuring runout, as runout typically refers to deviations from roundness or straightness rather than measuring distance to the ground.
Based on these interpretations, Option a is the correct answer. It accurately describes using the dial indicator to measure the variations (or the sweep) as you rotate the hub, which is the essence of runout measurement.
