For testing sensitivity on a 120,000 lb x 20 lb weigh beam, what test load should be applied?

When determining the appropriate test load for assessing the sensitivity of a weigh beam with a maximum capacity of 120,000 pounds and an increment of 20 pounds, it's crucial to understand the relationship between the test load and the increments of the scale's sensitivity.

The sensitivity of a weigh beam refers to the minimum change in weight that the device can accurately register. Since the scale increments are set at 20 pounds, applying a test load that is a fraction of this increment allows for an effective evaluation of the scale's response to small weight changes.

Applying a 20-pound test load allows for direct assessment consistent with the scale's sensitivity settings, as it will effectively demonstrate how accurately the scale responds when weights are measured at its defined sensitivity levels. A test load of 20 pounds matches the sensitivity increment, thereby providing an appropriate basis for testing.

Using other options such as 50 pounds, 10 pounds, or 100 pounds could either exceed the sensitivity threshold established (in the case of 50 or 100 pounds) or fall beneath it (for 10 pounds), rendering the assessment less effective or invalid. Thus, the optimal choice for testing sensitivity is indeed a test load of 20 pounds, aligning perfectly with the scale's specifications.