When should machines ideally be vibe tested for accurate results?

Machines should ideally be vibration tested under load and warmed up to ensure the accuracy of the results. This is critical because machinery operates differently when it is under load and at its normal operating temperature. During these conditions, the mechanical components experience the forces and behaviors that occur during standard operation.

When machines are warmed up, they have expanded due to heat, and any imbalances or misalignments are more likely to manifest as they would in real-world scenarios. Testing under load allows for observation of dynamic forces that occur during operation, which is essential to detect issues like resonance, misalignment, or imbalance that may not be evident when a machine is idle or cooled down.

Testing at any time or when machines are cold does not give a true representation of their performance, as various factors induced by operational conditions will significantly affect vibration patterns. Similarly, a stationary state may not capture the machine's operational characteristics effectively, leading to misleading conclusions.