Frequently Asked Questions about Laser Doppler Vibrometer

Surface roughness and other irregularities do not affect the measurement. However, rotating objects with irregularities (such as gears) are affected. Laser Doppler measurement measures the velocity component present on the target surface. Therefore, even if the target surface has irregularities, the velocity component due to vibration is the same at all points on the irregularity, so it is basically unaffected.

However, in the case of uneven surfaces on a rotating body, the direction of laser reflection can be significantly shifted, making measurement impossible. Basically, as long as the reflected beam returns to the photodetector (and the signal level indicator does not disappear), measurement is possible.

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*For the LV-1100/1600 series, the amount of reflected light can be checked using the indicator on the unit.