Radial vibration measurements directly from rotors using laser vibrometry: The effects of surface roughness, instrument misalignments and pseudo-vibration

► A major inconsistency in LDV measurements of rotor radial vibration is resolved. ► A first derivation of measured velocity on a polished-circular rotor is presented. ► The key effect of surface roughness and treatment is explored experimentally. ► By simulation, likely measurement errors and sensitivities are quantified. ► Together, these novelties form a practical guide to the user for rotor applications.