QTec® reinventing laser vibrometry

QTec® reinvents vibrometry by eliminating the root cause of noise delivering superior optical sensitivity, enabling high-fidelity measurements on all surfaces. In order to achieve this, QTec vibrometers use an innovative multi-path interferometer utilizing the highest quality signal of each path to achieve the best results. This patented technology is combined with the well-proven infrared Xtra sensor design for faster, easier measurements and a consistent result.

QTec - reinventing optical vibrometry

Influence of surface properties

The signal quality of a laser vibration measurement depends on the intensity of returned light. The surface determines the spatial distribution of backscattered light, and thus the information received by the photo detector from its position in space. 

The QTec® effect

The new, patented and highly innovative technology QTec® from Polytec significantly improves the signal-to-noise ratio (SNR). QTec® resolves even the finest details in the measurement signal, facilitating a straightforward post-processing. QTec® improves the results in almost any measurement and is particularly beneficial for engineered surfaces that move laterally or rotate. The average count can be drastically reduced to achieve the same SNR and measures are independent of the surface properties. 

Speckle effect on engineered surfaces

On an optically smooth surface, the reflected laser light is returned without loss to the photo detector. In the real world measurements are often carried out on surfaces that are optically rough. Here the light is no more reflected but scattered containing dark and bright speckles and the laser point starts looking grainy. This pattern changes with the particular perspective of an observer. This causes changes and occasionally no light return at the photo detector. These effects can cause broadband noise and unwanted dropouts with optical measurements. 
 

The solution: Change the perspective

The QTec® heterodyne multi-path interferometer provides exactly the capability to avoid reduced signal at the photo detector by using multiple detectors. Every detector represents an observer with a unique perspective, and thus a unique speckle pattern. As the pattern is random, it can be shown that the combination of the signals from the spatially distributed detectors results in a statistically stable signal level. The benefits of this so-called Diversity Reception apply to all engineered surfaces.

Ultra-fast electronics in the sensor head weight the detected signals in real-time and only the best part of the signal is transferred to a common output, making QTec® sensor heads compatible to current single channel vibrometer decoders.
The capability of QTec®  to measure independently of the surface properties makes it a safe choice for all applications providing fast, easy, robust results.