Here, you’ll find answers about Polytec’s advanced QTec® laser Doppler vibrometry, its benefits, applications, and product details. QTec® ensures high-precision, non-contact vibration measurements with superior signal quality across various surfaces.

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FAQ categories

General Information

 

What is QTec®?

QTec® is an advanced laser Doppler vibrometry technology by Polytec that enables high-precision, non-contact vibration measurements. It features high optical sensitivity, best signal-to-noise ratio on all surfaces, a broad frequency bandwidth, and no mass loading, making it ideal for demanding measurement tasks.

How does QTec® work?

QTec® uses a heterodyne multi-path interferometer with reception diversity, meaning multiple detection channels capture the best signal from the sample simultaneously. This results in a stable signal acquisition with a significantly improved signal-to-noise ratio.

What are the benefits of QTec®'s multi-path interferometry? 

QTec®'s multi-path interferometry addresses the root causes of noise in vibration measurements, delivering superior optical sensitivity. This technology enables high-fidelity measurements on all surfaces, reduces testing time, and ensures robust, unambiguous results.

What are the advantages of QTec® over conventional vibrometers?

  • Significantly reduced noise (-10 dB to -20 dB)
  • Stable measurements even on challenging surfaces and moving objects
  • Long-range measurement capability (up to 500 m)

 

What signal processing technologies are integrated into QTec®?

QTec® uses advanced FPGA decoding to ensure perfect phase synchronization between velocity, displacement, and acceleration outputs. It also offers multiple filtering options to reduce ambient noise.

What measurement ranges does QTec® cover?

QTec® offers:

  • Velocity ranges from 0.001 m/s to 30 m/s
  • Displacement measurement with resolutions as fine as 0.05 pm
  • Acceleration measurements up to 100 x 10⁶ m/s²

Applications and Use Cases

 

What are the key application areas for QTec®?

QTec® is ideal for:

  • Measurements on engineered and biological surfaces
  • Vibration analysis on rotating or laterally moving objects
  • Long-distance or hard-to-reach measurement targets
  • High-precision testing in automotive, aerospace, and medical engineering

How does QTec® handle measurements on dark or biological surfaces? 

QTec® interferometers are able to collect more light by utilizing multiple optical paths and diversity reception. This significantly improves the signal-to-noise ratio, enabling accurate measurements on challenging surfaces such as dark or biological materials. 

How does QTec® improve measurements on rotating objects?

QTec® effectively reduces speckle noise, which occurs when surface patterns change on rotating objects. This leads to more stable signal acquisition and improved analysis of bending vibrations and resonances.

How does QTec® perform in long-distance measurements? 

Atmospheric conditions influence the beam path of a laser by changing index of refraction along the path, so called eddies. The laser spot experience slight lateral movement in respect to the target. This causes speckle noise with conventional vibrometer setups. The QTec® technology maintains high optical sensitivity and signal integrity even at long distances, making it suitable for applications requiring measurements from afar, such as monitoring large structures or machinery.

Can QTec® technology be used in harsh environmental conditions? 

Yes, QTec®-based vibrometers are designed to operate effectively in challenging environments, including higher ambient temperatures. Their robust design ensures reliable performance across diverse industrial applications. As a non-contact sensing technology, it is well suited for measuring into test chambers and harsh environmental conditions. Vibrations in high electromagnetic field environments, radiation zones and high temperature situations are detected form a safe distance.  

 

QTec® Products

 

Which models are part of the QTec® product line?

The QTec® product line includes:

 

Can QTec® technology be integrated into automated testing environments? 

Yes, QTec®-based vibrometers, such as the VibroScan series, are designed for seamless integration into automated testing setups. They support drivers for both Linux and Windows, facilitating incorporation into inspection programs for quality control and pass/fail evaluations. For increasing the productivity in automated testing, solutions as RotoVib and RoboVib can be utilized. Both systems are open to use QTec vibrometers. 

Software and Connectivity

 

Can QTec® be controlled remotely?

Yes, QTec® features an integrated web server, allowing remote control via the internet. This enables flexible operation in hard-to-access or safety-critical environments. 

What software is used for data analysis?

QTec® is compatible with Polytec VibSoft and the PSV software, which provides comprehensive data acquisition and analysis. Additionally, special interfaces and drivers are available for OEM integration.