Red Seal Industrial Mechanic (Millwright) 2025 – 400 Free Practice Questions to Pass the Exam

To determine proper tension in a chain drive, measuring the vertical deflection of the chain when force is applied to the center is the most reliable method. This approach involves applying a specific force to the chain at its midpoint and observing how much it deflects. Proper tension is indicated when the deflection is within the manufacturer's specified limits.

This method ensures that the chain is not too loose, which can lead to skipping or excessive wear on the chain and sprockets, nor too tight, which can cause premature wear and stress on the bearings and other components. Using a combination of the applied force and measuring the deflection provides a clear and quantitative means of assessing the actual tension in a chain drive, making it the most accurate choice for this purpose.

In contrast, simply observing noise levels during operation may indicate issues, but does not provide a definitive measurement of chain tension. Inspecting the length of the chain is more about wear and elongation rather than proper tension at that moment, and checking wear on the sprockets can indicate overall system health but does not directly measure the chain's tension.