Certified Maintenance and Reliability Technician (CMRT) Practice Test

To determine the minimum shaft rotation required to obtain results with the E420 laser system in the presence of an obstruction, it is important to reference the operational guidelines of the laser alignment device. The correct answer indicates that a rotation of 70 degrees is sufficient to clear obstructions and allow for accurate data collection.

In this context, the E420 laser system is designed with the capability to align shafts and service machinery effectively. When an obstruction occurs, the system needs a certain amount of movement—specifically, 70 degrees—to ensure that the laser can accurately project and receive signals necessary for measurement. This range allows the system to bypass any potential interference caused by the obstruction, ensuring that data remains reliable.

The other specified angles, while representing various degrees of rotation, either do not provide adequate movement to clear typical obstructions or exceed the necessary amount, potentially leading to unnecessary complexities or extended measurement times without improving the outcome. Thus, understanding that 70 degrees strikes the balance between effectiveness and efficiency is crucial for safe and precise operation with the E420 laser system.