High accuracy and repeatability

High accuracy and repeatability

• Extensometers mounted using stable, low-vibration support arms.
• Housing provides protection against dirt and dust and inadvertent misalignment of the components.
• Exact synchronization of all measurement channels.
• Specially developed lighting provides continuous high-quality contrast ratios on the specimen, even with varying environmental conditions.
• Industrial-quality cameras and high-quality, low-distortion lenses.
• ZwickRoell extensometers exceed standards requirements, and are calibrated over the entire measurement range to ISO 9513 in the corresponding accuracy class.
• The videoXtens 2-120 HP and videoXtens biax 2-150 HP are calibrated in accuracy class 0.5 to ISO 9513, with the first calibration point starting at 20 μm.
• Additional calibration data-points for traceable, standard-compliant Young's modulus determination on plastics to ISO 527 (e.g. via additional calibration value at 25 µm) with the videoXtens 2-120 HP.
• Compliance with strict requirements for determination of the tensile modulus to ISO 527 Appendix C (videoXtens 2-120 HP and videoXtens biax 2-150 HP).
• The videoXtens biax 2-150 HP measures the change in width and Poisson’s ratio with an incomparable accuracy never before seen with non-contact extensometers.

Automatic centering

Automatic centering adjustment

• videoXtens tracks at half crosshead speed via the connection to the crosshead, keeping the testing operation automatically in focus and making optimum use of the measuring range (larger measuring range possible).
• This results in increased system measurement accuracy; the gauge marks shift less in the image and are captured in the center of the lens (low lens distortion).

Pattern recognition: Testing without gauge marks

Pattern recognition: testing with software gauge marks

• The innovative pattern-recognition algorithm allows virtual gauge marks to be applied to the specimen. The gauge marks can be changed retrospectively and re-calculated (Test Re-Run option). It doesn't get any more convenient!
• The essential requirement is for a pattern on the specimen - either a natural pattern due to a structured surface or an artificial pattern which can quickly be applied using a marker spray or by stippling.

Advantages and features

• The system is wear-free due to the fact that no mechanically movable components are used. Costs for wear parts and continuous maintenance do not apply.
• The videoXtens transverse strain extensometer does not need any specimen markings. It uses a highly developed edge detection algorithm. The absolute specimen width changes over time. It is determined using the specimen edges at up to ten different positions.
• The width can be determined at one or more locations (measuring lines). This allows measurement of offset yields in tensile tests to ISO 6892‑ 1, together with r & n-values to ISO 10113 and ISO 10275.
• The non-contact measurement method means that no contact forces emerge in the transverse direction. This makes it possible to test thin and sensitive specimens.
• In contrast to mechanical systems, the optical measuring system can be used for very small gauge lengths (15 mm and longer with a clamping length of 50 mm).
• The entire test sequence can be followed on the monitor and subsequent values can be recorded.
• 90° deflector with precision reflectors.
• The videoXtens transverse strain extensometer is available with a backlight screen.

Technical data