Language
Equipped for new challenges - with optical extensometers by Zwick
Ever-smaller specimen dimensions, contact-sensitive specimens, testing at high temperatures – the demands on modern measurement technology continue to grow. As contact-type extensometers increasingly reach their limits, Zwick’s range of optical extensometers has been expanded to meet this challenge.
Small and sensitive specimens
In numerous industries the trend is to use ever-smaller amounts of specimen material for tensile tests. This reduction in specimen size is partly due to smaller component dimensions and is also influenced by high raw-material costs. It is with these smaller specimens that the limitations of traditional extensometers become apparent; sensor arms of contact extensometers either no longer fit between the specimen grips or would damage the specimen prematurely before break.
Zwick’s laserXtens is the ideal solution. It uses the unique structures of the specimen surface to generate virtual gage marks, eliminating the need for traditional specimen marking. This has the additional advantage of saving time, especially with high specimen throughput or when used in automated systems, as no manual specimen preparation is required.
High temperatures and biaxial deformation
The limitations of contact extensometers are also evident in the high-temperature (HT) range, where gage marks cannot be used. The problem is easily solved by using laserXtens, which satisfies the requirements of Accuracy Class 1 of ISO 9513 (Class B2 of ASTM E83) in these applications also.
Materials are increasingly used for applications which require them to withstand biaxial loads; these may be biaxial tensile loads or tensile-torsion loads. The laser speckle principle enables measurement of these biaxial deformations using a single measuring system.
Fig. 1: Plastic tensile test in temperature chamber
Fig. 2: Tensile test on micro sepcimen
Fig. 3: Tensile test in tempered water bath
