Frequently Asked Questions about Laser Doppler Vibrometer

The Laser Doppler Vibrometer exhibits varying sensitivity (interferability) depending on the distance from the sensor end face (or lens end face) due to the configuration of the laser tube and the interference optical system used. By measuring at a distance with strong sensitivity, it is possible to achieve a good signal-to-noise ratio (S/N ratio), making sensitivity adjustment easier.

The distance here refers to the distance from the tip of the lens to the object being measured.

• The sensitivity is good at 170 mm from the sensor's end face (lens end face), and remains good at intervals of 200 mm thereafter. However, around 250 mm and 450 mm, the sensitivity decreases.
• When using close-up rings: for the LV-1300 and LV-1600 series (older products), even if the 'close-up rings' are used or changed to vary the measurement range, the above distance does not change.

In the LV-1700 series, the focal position where sensitivity is maximized is indicated on the sensor part with a '○ mark' as shown in the figure below.