Non-Contact Video Extensometers
The sophisticated new Tinius Olsen video extensometer is designed for the precise, non-contact measurement of specimen strain and is available in several different configurations.
The first Video Extensometer configuration uses a high resolution monochrome camera and advanced high speed image processing such that the point to point real-time video technology for continuous strain measurement through tensile break or compressive rupture. This single camera configuration uses a unique lens, designed for materials testing use, and is ideal for measuring low strain values with very high precision.
Key features include a high resolution of better than 1/100,000 of lens FOV, a high system accuracy of 0.5%, automatic gauge search and find, and the ability to use both longitudinal and transverse multiple gauge lengths. Although it is not necessarily required, a cool lighting source is included so that strain point tracking is not lost due to changes in ambient conditions.
Preparation of the test specimen is quick and easy. Any visible marking can be used for pattern recognition, and these can be natural patterning on the specimen surface, pen marks, blob markers, punched gauge marks or a sprayed speckle pattern. The pattern recognition algorithms work on edge detection, so the more detailed the pattern, the more accurate the pattern recognition.