Introducing Laser Doppler Vibrometry
- christiandepodesta
- Nov 10
- 2 min read
Full Matrix is now offering vibration analysis as a service, using our Polytec PSV-500 3D Scanning Laser Vibrometer.
Laser vibrometry is the gold standard for vibration measurements, offering engineers and designers a way to visualise and quantify the minute dynamic movements of their products.
What does a Laser Vibrometer do?
A scanning laser vibrometer measures the velocity across a grid of points on the surface of an object, to build a complete map how the surface moves.
Laser Vibrometry is used for quantifying any and all systems that vibrate to:
Produce stunning visualisations of modal deflection patterns
Perform quantitative analysis of resonant behaviour
Map sources of noise unwanted noise
Analyse musical instruments and hi-fi audio components
Standardise testing ultrasonic equipment
Explore the universe of sound in materials, not coupled to the air
However, laser vibrometry is not only a tool for , acoustic measurements can be used as a tool to analyse dynamic responses of any object, including:
Mapping points of stress in a design
Identifying deflection patterns of components exposed to rough conditions
Experimental validation of finite element analysis
Non-destructive testing
How does it work?
When the light from a laser reflects off of a moving surface, the wavelength (colour) of the returned light is shifted to be slightly bluer, if the object is moving closer, or slightly more red if the object is moving away. This phenomenon is known as the Doppler effect, and it is the principle which allows a Doppler Vibrometer to measure minute movements with incredible precision.
A single laser vibrometer, however, only allows you to measure the component of motion, along the direction of the laser beam. A 3D-Doppler vibrometer employs three separate laser vibrometers, aimed on the same point from three different positions. This allows the system to resolve the complete 3D velocity vector at every point on the surface.
A scanning laser vibrometer synchronises the movements of all three lasers to trace out a grid projected onto a 3D object, measuring the vibrations at every point on the surface. The PSV-500 Vibrometer integrates an additional distance measurement laser, to capture the geometry of your surface. This produces an accurate 3D model of your object, onto which the vibration measurements can be mapped.
What makes this special?
Contactless measurement | Measurement is not affected by the weight of a transducer, giving accurate results for lightweight and complex structures. |
High Spatial Resolution | Capable of capturing hundreds of points, with sub-millimetre resolution on small devices, or across large surfaces. |
Frequency Range | Sensitive across the frequency spectrum, from DC to audible frequencies and beyond, up to 2 MHz Ultrasound. |
Dynamic Range | Can resolve minute vibrations from 0.01 µm/s, all the way up to 30 m/s. |
Extreme Conditions | Optical measurement is suited to extremely hot or cold surfaces, and those in magnetic or otherwise dangerous environments. |
True Experimental Data | Produces real-world data from fragile or unique objects, manufacturing defects, or composite materials which are not well described by computer modelling. |
How can this help me?
Reach out now to find out what vibrometry measurements can do for you:
Comments