When testing the speed indicator, what speed range should be used for accuracy checks?

The appropriate speed range for accuracy checks during speed indicator testing is from 10 to 30 MPH. This range is significant because it effectively represents operational speeds that are commonly encountered in rail transport. Testing within this specific range allows for the detection of any inaccuracies that may not be evident at lower speed levels, ensuring that the indicator provides a reliable reading under typical working conditions.

Moreover, the choice of 10 to 30 MPH aligns with safety standards and operational requirements, as it encompasses speeds that are crucial for performance verification without extending into ranges that may not reflect everyday usage or could introduce additional variables that complicate testing accuracy. By focusing on this range, the procedure maximizes the efficacy of the testing outcome, ensuring that the speed indicator provides consistent and reliable performance in real-world scenarios.