For unmarked weighbeam equipped railway track scales, what is the sensitivity requirement?

The sensitivity requirement for unmarked weighbeam equipped railway track scales is defined as either 3d or 100 lb, whichever is less. This means that the scale must be able to detect weight changes down to a sensitivity of 3d (where "d" represents the smallest division of the scale) or a threshold of 100 lb, but only the lower of the two values is acceptable.

For instance, if the smallest division of the scale (3d) results in a sensitivity requirement of less than 100 lb, then that smaller value would apply. This ensures a standard of precision in measuring train weights, which is critical for safety, regulatory compliance, and operational efficiency in railway operations.

In contrast, the other options present sensitivity thresholds that exceed the requirements specified for unmarked weighbeams. Choosing an option that suggests higher sensitivity can lead to inaccuracies or operational inefficiencies, as these measures would not meet the established regulatory standards for railway weight measurement.