What is order analysis in NVH testing and why is it important?

Order analysis correlates noise and vibration with rotating component speeds using order tracking. An order is a multiple of rotational frequency - e.g., 2nd engine order is twice engine RPM. Analysis extracts order magnitude and phase versus RPM, separating engine orders from tire/driveline orders. This identifies source contributions, reveals resonance amplifications at specific speeds, and enables targeted countermeasures. Waterfall and colormap displays visualize order behavior across sweeps. Order tracking requires precise RPM reference and specialized signal processing to maintain amplitude accuracy during speed changes.