Quality Assurance with Active Thermography inSeries Test at Zwickau Volkswagen Plant
Non-destructive testing methods are becoming increasingly more important in the industry. One reason is that they
cost much less than other test methods. As a very elegant method, the active heat flow thermography method is now
firmly established as a powerful method of non-contact and non-destructive testing of products of different
manufacturing technologies.

Image 1: Robot in test position

The quality assurance staff at Volkswagen Sachsen GmbH in Zwickau (Germany) have successfully relied on thisinnovative test method for several years. Working closely with InfraTec, they have developed tailored applications fortheir measurement tasks and gradually adapted them to the types of vehicles and specific local conditions. Specialists
there test laser welds of body components with two- and three-plate connections. Since the integration of themodular production kit MPB in the factory in Saxony, the testing became even more comprehensive. Now, there arechecked technologically more sophisticating welded seams at the test side in a fully automated way.
With this thermographic check, Sven Beier and his team can detect even the smallest details of car bodies. They
examine and evaluate bodies and side panels of different vehicle types, which is not an easy task. After all, a single
component can have up to 250 individual welds, depending on vehicle model. Performing the testing in a three-shiftoperation, up to 3,500 laser welds can quickly pass through this non-destructive inspection by the end of each day.
Ralf Albrecht, head of quality assurance for car chassis, is especially pleased about the newfound freedom: "Byautomating the testing facility, the test throughput has been significantly increased and made more flexible."
The heart of this test system is the special flash head, developed jointly by Volkswagen and InfraTec, where in addition
to the powerful flash lamp, a thermal imaging camera is also integrated. Designed to replace the previous standard
flash heads, this new development enables both the so-called incident and transmitted light test. Sven Beiersupervised the test system on site and is absolutely convinced of its unique combination of industry flash lamp andhigh-end thermographic camera ImageIR®: "With the new flash head construction, we reach significant greater life
expectancy when compared to the previous solution." A car body group is tested using two special flash heads,
mounted on powerful 7-axis robots. After the program starts, an automatic execution of all programmed test
Page 1© InfraTec 2011 (All the stated product names and trademarks remain in property of their respective owners.)
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thermo@InfraTec.de
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Quality Assurance with Active Thermography inSeries Test at Zwickau Volkswagen Plant
positions of a test sequence is carried out. The team, however, can change at any time in a subsection or test
sequence to test single laser welds.
In active thermography, a defined trigger, high-energy flash
sends a heat pulse to the laser weld to be tested. This createsa heat flow that causes a temperature change at the surfaceof the object. The lateral distribution of temperature change
and the time course is recorded by a high-sensitivity, highspeed thermographic camera of the ImageIR® series. This
creates a real-time sequence of infrared images and sends
them to a PC, where they are stored. Flaws or defects lead toa change in heat flow and cause a characteristically alteredtemperature distributions on the component surface. A test
software, developed by InfraTec in collaboration with thequality assurance team at the Volkswagen plant in Zwickau,
analyses the stored sequences and provides the analysis
results and other data. The inspector can then gather detailed
information from this data about the condition of the welds
and, where appropriate, promptly take action to ensure
quality remains high. This intuitive test software enables a fulldocumentation of the test results, as well as operator actions
and can be individually adapted to each test position.
This procedure further increases the testing security
compared to destructive testing, even with significantly
shorter testing times and lower costs. In result, this provides
an additional benefit in quality and quantity concerning theentire production.

Abb. 2:

From left: Andreas Zein, Sven Beier and Ralf Albrecht

Abb. 3:High-End-Thermography Camera ImageIR® by InfraTec

Page 2© InfraTec 2011 (All the stated product names and trademarks remain in property of their respective owners.)
Headquarters

InfraTec GmbHInfrarotsensorik und Messtechnik
Gostritzer Straße 61 – 63
01217 Dresden / GERMANY

USA office

PhoneFax
E-mail+49 351 871-8630+49 351 871-8627thermo@InfraTec.de
www.InfraTec.eu

InfraTec infrared LLC
5048 Tennyson Pkwy.
Plano TX 75024 / USAPhone
E-mail+1 844-226-3722 (toll free)thermo@InfraTec-infrared.com
www.InfraTec-infrared.com