The permanent increasing requirements of product quality raise a demand for updated and more effective methods of testing and analysis. The measuring method requires to be used on-line, full field, non destructive and without contact. For solving such problems, whole field interferometric laser optical methods are predetermined. Their sensitivity and accuracy are very high but they are sensitive as well against environmental disturbances like thermal air waves or lower frequency vibrations and therefore they are not suited for application in production lines.

The laboratory for photoelasticity, holography and shearography (SHS) in the design institute MK, Dept. ME, University Gh Kassel has developed and manufactured a compact and versatile measuring unit for testing quality and analysing strains and vibrations, which is relatively insensitive against external disturbances compared to holographic interferometry (ESPI). The shearographic measuring device is characterised by its simple set-up and gets over the above mentioned obstacles of holography, so that they can be applied in industry.

Shearwin is a software tool for performing the interferometric measurements as well as for evaluating the test results. Based on different software packages, Shearwin offers facilities to individual research work and can be adapted to automatic solutions for common industry problems. According to his background and ambition, the user is able to choose between individual control and progress of measurement or automatic routines. Making comprehensively  use of the automatic facilities, the combination with the compact measuring device developed by the Lab SHS and basic computer hardware is recommended as detailed in the following table:

Exposure of Speckle interferograms in different ways with phase shifting technique

Various Phase-Filters

Demodulation and Evaluation of phase maps

Fast Fourier Transformation and evaluation of phase maps

Graphical representation of results

The following functions include the above listed elements of measuring and evaluation:

Holography: Auto-measuring tools in-plane and out-of-plane

Shearography: Auto-measuring tools in-plane and out-of-plane

System requirements:

-   Computer with Windows 3.x operating system or Windows NT (available begin next millenium

-   Matrox Pulsar graphic board

-   one or two monitor solution

-   (I/O card) supplementary for 3D strain analysis

-   Piezo card for phase shifting technique

-          Testing an object by analysing strains you supplementary need an I/O card to control the shutters of the measuring set-up.