Continuous measurement through tensile break or compressive rupture, means the Video Extensometer is perfect for precise, non-contact measurement of specimen strain.
The system works by acquiring an image of the specimen and using pattern recognition technology to lock onto a minimum of two targets, which can equate to a number of different gauge lengths. These targets can be defined by the user, who can set them to any gauge length as required.
As the specimen is tested, the software tracks the point-to-point movement of these targets from camera frame to frame, and strain data is calculated in real time. Since multiple gauge lengths are possible in both longitudinal and transverse directions, the determination of r and N values is simple and straightforward.
♦ Maximise measurement versatility with point-to-point methodology
♦ Measure fragile, brittle, irregular and other difficult specimens without contact
♦ Meet requirements for ASTM E83 Class B1, ISO 9513 Class 0.5 and EN 10002-4 standards
♦ Choose axial, axial-transverse, orthogonal, rotational measurements
♦ Use multiple cameras and longitudinal gauge lengths to study complex events
♦ Integrate measurements into results and reports from Horizon software
♦ Capture and archive video images for later review
Tinius Olsen lenses for video extensometer systems fall into two categories:
♦ Materials testing lenses - precision, high-resolution lenses that have a fixed focal length.
♦ General purpose lenses - variable focal lengths with variable, and larger, fields of view. Moving them further from the specimen increases the amount of strain they can measure.
Materials testing lenses come in a wide range of physical sizes. Because they have a fixed focal length, they must be mounted on one of the many translation stages Tinius Olsen offers, which in turn are mounted on a robust, rigid tripod, or bracketing system mounted to the test frame. This allows the camera and lens to moved backwards or forwards to bring the specimen and markings into focus.