videoXtens Extensometer

videoXtens is used for optical measurement of extension on contact-sensitive and highly elastic materials.

This extensometer provides non-contact measurement of tensile, compression and flexural deformation on all types of plastics, metals, rubber, composites and foils, as well as two-dimensional point shifts within a matrix, eg. B. on components. 

 It is also suitable for determining the change in width, the r-value according to ISO 10113, ISO 10275 and the tensile yield strength in accordance with ISO 6892-1. Where international standards demand high accuracy, the videoXtens is the perfect solution. Also, because the influence of the user is practically excluded and ensures reliable measurement results.

Advantages and features of Extensometers

Easy to operate

  • Automatic gauge-mark recognition and acquisition of initial gauge-length L0.
  • Tamper-proof: anti-tamper paint is applied to the lenses for the complete system so nothing can be adjusted. An important requirement for reliable test results.
  • Easy alignment to the specimen: videoXtens is centrally aligned to the gauge marks via the connection to the crosshead (option).
  • Compensation for different specimen thicknesses plus testing shear specimens.
  • Wear-free system = low-maintenance. The systems also feature an extremely long service life.
  • Connection to non-ZwickRoell machines via ±10V interface.

High accuracy and repeatability

  • Extensometer mounted using stable, low-vibration holders.
  • Housing provides protection against dirt and dust and inadvertent loss of adjustment of components.
  • Exact synchronization of all measurement channels.
  • Specially developed lighting provides high-quality contrast ratios on the specimen at all times, even with varying environmental conditions.
  • Industrial-quality cameras and high-quality, low-distortion lenses
  • ZwickRoell extensometers exceed the requirements of the standards and are calibrated over the entire measurement range in their individual accuracy class to ISO 9513.
  • videoXtens 2-120 HP is calibrated with the first calibration point from as early as 20 µm in Accuracy Class 0.5, ISO 9513.
  • 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 videoXtens 2-120 HP.

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).

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.

videoXtens 2-120 HP

videoXtens 2-120 HP includes two high-resolution cameras. Their overlapping fields of view are combined into one large field via ZwickRoell array technology. Markings leaving the field of view of one camera are automatically transferred to that of the next camera. This provides a greater field of view with high resolution.

The flexible tunnel can be extended or retracted to suit individual requirements. By minimizing environmental influences it creates the conditions required for a low-noise signal. It also contains integrated LEDs which provide uniform specimen illumination.

The system can easily be attached to a ZwickRoell temperature chamber via a tunnel adapter. This results in a closed system, minimizing signal interference due to air currents.

Application videoXtens 2-120 HP

 Plastics to ISO 527-1 or ASTM D638

Requirements of ISO 527-1 for determination of tensile modulus: max. error ± 1 µm / ±1.5 µm when measuring the differential displacement between two measuring points (with elongation of 0.05% and 0.25% of the initial gauge length, with an initial gauge length L0 of 50 mm / 75 mm.
We recommend self-adhesive gauge marks (strips).

  • Specific advantages in this application
  • Satisfies the exacting calibration requirements for tensile modulus values to ISO 527-1, Annex C.
  • High-accuracy measurement of tensile modulus.
  • ZwickRoell extensometers exceed the requirements of the standards and are calibrated over the entire measurement range to Accuracy Class 0.5, ISO 9513.
  • Even brittle-fracturing plastics specimens can be tested without damaging the extensometer.
  • High-accuracy testing with ZwickRoell temperature chamber, including with determination of tensile modulus to ISO 527-1.
  • Enclosed system - connection via tunnel when testing in temperature chamber.
  • Resistant to environmental influences (e.g. air currents, variations in lighting); flexible tunnel minimizes signal interference.
  • Optimum, uniform specimen illumination by LEDs incorporated into the tunnel.

 

 

 

 

Fiber composites 

  • Tensile tests on filament strands and laminates of fiber composites, e.g to ISO 527-4/5, ASTM D3039, ASTM D4018
  • In-plane shear tests (±45° method). In-plane shear response to ISO 14129 and ASTM D3518 (software option Second Measurement Axis required).
  • Specific advantages in this application
  • Brittle-fracturing fiber composites can be tested up to break without damaging the extensometer.
  • Accuracy Class 0.5 to EN ISO 9513. ZwickRoell extensometers exceed the requirements of the standards and are calibrated over the entire measurement range to Accuracy Class 0.5, ISO 9513.
  • Accuracy Class B1 to ASTM E83 from a gauge-mark separation of 15mm.
  • High-accuracy testing with ZwickRoell temperature chamber, including with determination of tensile modulus to ISO 527-1.
  • Enclosed system - connection via tunnel when testing in temperature chamber.
  • Resistant to environmental influences (e.g. air currents, variations in lighting); flexible tunnel minimizes signal interference.
  • Optimum, uniform specimen illumination by LEDs incorporated into the tunnel.

videoXtens 1-120

videoXtens 1-120 includes a camera plus lens. The lens is supplied security-painted, with the housing screw-assembled to prevent changes to the system.

The system can easily be attached to a ZwickRoell temperature chamber via a tunnel plus adapter. This results in a closed system, minimizing signal interference due to air currents.

Application videoXtens 1-120

 ISO 527-1 without tensile modulus determination 

  • Specific advantages in this application
  • Simple, compact system for determination of strain at yield stress (curve types b & c).
  • Even brittle-fracturing plastics specimens can be tested without damaging the extensometer.

Testing A50 or A80 metal sheets to ISO 6892 

  • Method B or A2, without r-value determination
  • e.g. for determination of Rp0.2, Ag, A
  • Specific advantages in this application
  • Compact system for easy testing to standard - with total absence of specimen contact
  • No influence on specimens: thin metal sheets or metal foils are sensitive to contact, making the non-contact videoXtens the ideal solution. It has no influence on material characteristic values.

Tensile test on geotextiles / geogrids to EN ISO 10319 

  • videoXtens can measure extremely wide specimens. As videoXtens is non-contacting specimens width is irrelevant.
  • Even specimens prone to whipping can be tested without damaging the extensometer.
  • Pattern recognition eliminates the need for specimen marking.
  • Modulus values can also be determined in the initial range, e.g. gradient at x% strain.

videoXtens 1-270

videoXtens 1-270 includes a camera plus lens. The lens is supplied security-painted, with the housing screw-assembled to prevent changes to the system.

The system can easily be attached to a ZwickRoell temperature chamber via a tunnel plus adapter. This results in a closed system, minimizing signal interference due to air currents.

Application videoXtens 1-270

Tests on elastomers to ISO 37, ASTM D412 or DIN 53504 

  • L0 = 10, 20 or 25 mm
  • Specific advantages in this application
  • Connection to crosshead ensures the gauge marks are always central and optimum use is made of the measuring range.
  • Unimpeded view of the specimen; no blind spot due to specimen grips - videoXtens is centrally aligned and tracked.
  • Accuracy Class 1: modulus values can also be determined in the initial range, e.g. stress at 10% strain.
  • Large measuring range.
  • Specimen whips at break and may damage contact-type systems.
  • Sensitive specimens are not affected by knife-edges - non-contact testing.
  • High accuracy, including at temperature with ZwickRoell temperature chamber in range from -55 to +250°C.
  • Enclosed system - connection via tunnel when testing in temperature chamber.

Testing ropes (textile) 

  • Specific advantages in this application
  • Connection to the crosshead ensures the gauge marks are always central and optimum use is made of the measuring range.
  • Unimpeded view of the specimen; no blind spot due to specimen grips - videoXtens is centrally aligned and tracked.
  • Accuracy Class 1: modulus values can also be determined in the initial range, e.g. stress at 10% strain.
  • Large measuring range.
  • Specimen whips at break and may damage contact-type systems.
  • Sensitive specimens are not affected by knife-edges - non-contact testing.
  • High accuracy, including at temperature with ZwickRoell temperature chamber in range from -55 to +250°C.
  • Enclosed system - connection via tunnel when testing in temperature chamber.

Testing films to ISO 527-3 

  • Specific advantages in this application
  • Accuracy Class 1 (from measurement travel 0.24 mm at least), allowing modules to be determined in the initial range also.
  • Sensitive specimens are not affected by knife-edges - non-contact testing.
  • Pattern recognition: a pattern is quickly generated over the entire specimen by stippling or stamping.
  • Connection to crosshead ensures the gauge marks are automatically always central and optimum use is made of the large measuring range.
  • Outflow of the film specimens during the test does not restrict the measuring range and does not therefore need to be allowed for.
  • Time-saving for research: no specimens are wasted due to break outside L0. Test Re-Run option and pattern recognition allow L0 to be adjusted retrospectively and the test re-calculated so that the break then lies within L0. Alternative: the strain distribution also included in this option automatically positions L0 around the area of highest strain if multiple gauge marks were placed before the test.

videoXtens 3-300

videoXtens 3-300 includes three high-resolution cameras. Their overlapping fields of view are combined into one large field via ZwickRoell array technology. Markings leaving the field of view of one camera are automatically transferred to that of the next camera. This provides a greater field of view with high resolution.

The housing contains an optical filter disc which can be moved in and out via a lever.

The system can easily be attached to a ZwickRoell temperature chamber via a tunnel plus adapter. This results in a closed system, minimizing signal interference due to air currents.

Application videoXtens 3-300

Testing films to ISO 527-3 

  • Specific advantages in this application
  • High measuring range combined with high resolution.
  • Versatile: the videoXtens 3-300's high measuring range and high resolution allow it to be used for other tests also.
  • Sensitive specimens are not affected by knife-edges - non-contact testing.
  • Pattern recognition: a pattern is quickly generated over the entire specimen by stippling or stamping.
  • Connection to crosshead ensures the gauge marks are automatically always central and optimum use is made of the large measuring range.
  • Outflow of the film specimens during the test does not restrict the measuring range and does not therefore need to be allowed for.
  • Time-saving for research: no specimens are wasted due to break outside L0. Test Re-Run option and pattern recognition allow L0 to be adjusted retrospectively and the test re-calculated so that the break then lies within L0. Alternative: the strain distribution also included in this option automatically positions L0 around the area of highest strain if multiple gauge marks were placed before the test.

Testing belts/straps, determination of strain at break 

  • e.g. L0: 100 mm or 200 mm
  • Specific advantages in this application
  • Connection to crosshead ensures the gauge marks are automatically always central and optimum use is made of the large measuring range. Although an extremely large amount of material runs out of the specimen grips, the measuring range is not restricted.
  • No specimen marking required thanks to pattern recognition. This uses the natural texture of the specimen.
  • Specimens are extremely prone to whipping - no damage to extensometer at break, entire test can be tracked.
  • Transverse strain can also be measured via the Second Measurement Axis software option. For example, in the case of belts which spread under tensile load due to the fabric structure.
  • No specimens are wasted due to break outside L0: Test Re-Run option and pattern recognition allow L0 to be adjusted retrospectively and the test re-calculated so that the break then lies within L0. Alternative: the strain distribution also included in this option automatically positions L0 around the area of highest strain if multiple gauge marks were placed before the test.

ISO 6892 Method B or A2 + r-value 

  • Specific advantages in this application
  • Versatile: the videoXtens 3-300's high measuring range and high resolution allow it to be used for other tests also.
  • No influence on specimens: aluminum specimens or metal foils are sensitive to contact, making the non-contact videoXtens the ideal solution. It has no influence on material characteristic values.
  • Connection to crosshead ensures the gauge marks are automatically always central and optimum use is made of the large measuring range.
  • The additional camera for change-in-width measurement (including r-value determination option) is always trained automatically on the center of the field of view and therefore on the specimen center.
  • More accurate determination of change in width: width is measured at precisely the location on the specimen established initially via measuring lines, e.g. centrally between the gauge marks. Up to 10 measuring lines can be defined for change-in-width measurement.

Concrete-reinforcing steel to DIN 488, ISO 15630 

  • e.g. Le 100 mm
  • Specific advantages in this application
  • High measuring range combined with high resolution.
  • No specimen marking required: the natural pattern on the specimen (ridges) is used to form virtual gauge-marks.
  • Saving on specimen material cost: no specimens wasted due to breaks outside L0. Test Re-Run option and pattern recognition allow L0 to be adjusted retrospectively and the test re-calculated so that the break then lies within L0. Alternative: the strain distribution also included in this option automatically positions L0 around the area of highest strain if multiple gauge marks were placed before the test.
  • Brittle-fracturing specimens: no damage to extensometer at break thanks to non-contact measurement.
  • Automatic centering: extensometer tracks via connection to crosshead. This also results in a larger measuring range and the system is automatically positioned centrally to the gauge length at all times.

videoXtens in Use

7:42

Ribbed steel test with 2-camera videoXtens extensometer

The test re-run software options and strain distribution facilitate measurement across the entire length of the specimen and a subsequent recalculation of the strain

Software options 

testXpert III testing software offers various options for precise, traceable non-contact extension and strain distribution measurement. 

Test Re-Run and strain distribution

The optional Test Re-Run module enables retrospective recalculation of strain using an image series recorded during a test but employing a different initial gauge-length (provided multiple marks are present). This can be particularly advantageous in component testing, for example, when it is necessary to evaluate local strain at different locations, or in standard tensile tests when specimen necking has occurred outside the original initial gauge-length.

The recalculated strain can naturally be synchronized retrospectively with the other measured values via the testXpert testing software.

Strain Distribution option

The Strain Distribution option enables determination of local strains at multiple measuring locations along the specimen gauge-length. These are available as channels in testXpert. Up to 16 measuring locations are automatically recognized and evaluated during the test. This option also allows automatic real-time symmetrical adjustment of the initial gauge-length around the necking (to ISO 6892-1, Annex I).

Video Capturing

Video capture is a recording of the test (without retrospective recalcualation). The recording is synchronized with the measured curve, enabling the test to be viewed retrospectively. The option includes no hardware, as recording and synchronization take place entirely via the videoXtens system.
Please note: Video Capturing is included from testXpert II Version 3.61 onwards and videoXtens software V6.6 (supplied from July 2015 onwards). In the case of older software versions, please always offer the free Video Capturing option (Item No. 049467).

2D dot matrix

This option allows two-dimensional measurement of dots applied to a planar specimen surface. This enables determination of local strains and specimen inhomogeneities under load. X and Y co-ordinates plus the distances between dots are available as measured values.

Up to 100 measurement dots can be measured in any desired arrangement or in matrix form. Display in testXpert III is limited to 15 channels.

This option uses only one camera for measurement; any other cameras present are switched off beforehand.

Optional second measurement axis 

This option allows biaxial measurement; transverse strain (e.g. change in width) can be recorded at the same time as longitudinal strain. Alternatively, change in width can naturally be measured alone.

  • Two versions are available for measurement of transverse strain:
  • measurement directly on the specimen edge with no additional markings (required for determination of r-value); a backlight is required for this version
  • measurement on the specimen surface using dot markings or sprayed-on pattern; with this version specimen illumination is via incident light.

Deflection measurement 

videoXtens can also be used for flexure tests. There are several options for measuring specimen deflection, depending on the type of test and the specimen condition and properties:

  • measurement using incident light via marks on the specimen
  • measurement using backlight on the specimen lower edge
  • measurement of deflection in the test axis or of the polynomial approximation of the curve.

Maximum deflection that can be measured: with videoXtens the maximum deflection corresponds to the FOV; with videoXtens Array to 1/3 of the total FOV (deflection is measured with one camera only in this case).

Technical Overview

videoXtens 2-120 HP

Type

videoXtens 2-120 HP

Item No.

1034953

Field of view (FOV)

with test area width 440 mm [AllroundLine] and zwickiLine

min. 120 x 50

mm

with test area width 640 / 1040 mm [AllroundLine]

min. 140 x 60

mm

Initial gauge length

with test area width 440 mm [AllroundLine] and zwickiLine

5 to 100

mm

with test area width 640 / 1040 mm [AllroundLine]

5 to 110

mm

Measurement travel, max.

with test area width 440 mm [AllroundLine] and zwickiLine

110 - initial gauge length

mm

with test area width 640 / 1040 mm [AllroundLine]

130 - initial gauge length

mm

Measurement travel, max, with initial gauge length 50 mm

with test area width 440 mm [AllroundLine] and zwickiLine

60 (120 % elongation)

mm

with test area width 640 / 1040 mm [AllroundLine]

80 (160 % elongation)

mm

Measurement travel, max, with initial gauge length 75 mm

with test area width 440 mm [AllroundLine] and zwickiLine

35 (45 % elongation)

mm

with test area width 640 / 1040 mm [AllroundLine]

55 (75 % elongation)

mm

Resolution at room temperature

0.15

µm

Resolution to ISO 9513 in ZwickRoell temperature chamber

at -20 to +250 °C

max. 0.4

µm

at -40 °C

max. 0.6

µm

at -55 °C

max. 0.8

µm

Image rate / measured-value acquisition rate, max.

500

fps / Hz

Max. test speed

1000

mm/min

Dimensions

Height

175

mm

Width

310 to 560

mm

Depth

91

mm

Length of tunnel

70 to 320

mm

Specimen thickness

0 to 20

mm

Weight (incl. tunnel), approx.

10

kg

Accuracy class

to EN ISO 9513.

0.5

to ASTM E83

B1 from gauge length 15 mm

Scope of delivery

Measuring head with 2 digital cameras incl. 2 lenses

Tunnel for minimizing negative environmental conditions (e.g. air currents), with integrated LED lighting

Software for image acquisition and evaluation

Accessory case with alignment and marking aids

INC module (RS module for tC)

videoXtens 1-120

Type

videoXtens 1-120

Item No.

1043969

Field of view (FOV)

With test area width 440 mm [AllroundLine] and zwickiLine

120 x 95

mm

With test area width 640 / 1040 mm [AllroundLine]

150 x 120

mm

Initial gauge length

With test area width 440 mm [AllroundLine] and zwickiLine

5 to 100

mm

With test area width 640 / 1040 mm [AllroundLine]

5 to 120

mm

Displacement measurement, max.

With test area width 440 mm [AllroundLine] and zwickiLine

110

mm - initial gauge length [mm]

With test area width 640 / 1040 mm [AllroundLine]

140

mm - initial gauge length [mm]

Measured displacement, max at initial gauge length 50 mm

With test area width 440 mm [AllroundLine] and zwickiLine

60

mm (120 % elongation)

With test area width 640 / 1040 mm [AllroundLine]

90

mm (180 % elongation)

Measured displacement, max at initial gauge length 75 mm

With test area width 440 mm [AllroundLine] and zwickiLine

35

mm (45 % elongation)

With test area width 640 / 1040 mm [AllroundLine]

65

mm (85 % elongation)

Measured displacement, max at initial gauge length 80 mm

With test area width 440 mm [AllroundLine] and zwickiLine

30

mm (35 % elongation)

With test area width 640 / 1040 mm [AllroundLine]

60

mm (75 % elongation)

Resolution at ambient temperature

With test area width 440 mm [AllroundLine] and zwickiLine

0.5

µm

With test area width 640 / 1040 mm [AllroundLine]

0.6

µm

Resolution to ISO 9513 in ZwickRoell temperature chamber

At -20 to +250 °C

max. 0.6

µm

At -40 °C

max. 0.9

µm

At -55 °C

max. 1.2

µm

Frame rate / maximum measured-value acquisition-rate, max.

500

fps / Hz

Max. test speed

1000

mm/min

Dimensions

Height

175

mm

Width

306

mm

Depth

91

mm

Specimen thickness

0 to 20

mm

Weight, approx.

7.5

kg

Accuracy class

To EN ISO 9513

1

Scope of delivery

Measuring head with digital camera

Lens (25 mm)

Software for image acquisition and evaluation

Accessory case with alignment and marking aids

INC module (for tC: RS module)

videoXtens 1-270

Type

videoXtens 1-270

Item No.

1043968

Field of view (FOV)

with test area width 440 mm [AllroundLine] and zwickiLine

270 x 215

mm

with test area width 640 / 1040 mm [AllroundLine]

330 x 260

mm

Initialgauge length

with test area width 440 mm [AllroundLine] and zwickiLine

5 to 220

mm

with test area width 640 / 1040 mm [AllroundLine]

5 to 260

mm

Measurement travel, max.

with test area width 440 mm [AllroundLine] and zwickiLine

260

mm - initial gauge length [mm]

with test area width 640 / 1040 mm [AllroundLine]

320

mm - initial gauge length [mm]

Measurement travel, max, with initial gauge length 10 mm

with test area width 440 mm [AllroundLine] and zwickiLine

250 (2500 % elongation)

mm

with test area width 640 / 1040 mm [AllroundLine]

310 (3100 % elongation)

mm

Measurement travel, max, with initial gauge length 20 mm

with test area width 440 mm [AllroundLine] and zwickiLine

240 (1200 % elongation)

mm

with test area width 640 / 1040 mm [AllroundLine]

300 (1500 % elongation)

mm

Measurement travel, max, with initial gauge length 25 mm

with test area width 440 mm [AllroundLine] and zwickiLine

235 (940 % elongation)

mm

with test area width 640 / 1040 mm [AllroundLine]

295 (1180 % elongation)

mm

Resolution at room temperature

with test area width 440 mm [AllroundLine] and zwickiLine

0.9

µm

with test area width 640 / 1040 mm [AllroundLine]

1.2

µm

Resolution to ISO 9513 in ZwickRoell temperature chamber

at -20 to +250 °C

max. 1.0

µm

at -40 °C

max. 1.3

µm

at -55 °C

max. 1.5

µm

Image rate / measured-value acquisition rate, max.

500

fps / Hz

Max. test speed

1000

mm/min

Dimensions

Height

175

mm

Width

306

mm

Depth

91

mm

Specimen thickness

0 to 20

mm

Weight, approx.

7.5

kg

Accuracy class

with test area width 440 mm [AllroundLine] and zwickiLine

to EN ISO 9513.

1

with test area width 640 / 1040 mm [AllroundLine]

to EN ISO 9513.

1 from measurement travel 0.24 mm

Scope of delivery

Measuring head with digital camera

Lens (12 mm)

Lens correction target

12 x 12

mm

Software for image acquisition and evaluation

Accessory case with alignment and marking aids

INC module (RS module for tC)

videoXtens 3-300

Type

videoXtens 3-300

Item No.

1043970

Field of view (FOV)

with test area width 440 mm [AllroundLine]

320 x 110

mm

with test area width 640 / 1040 mm [AllroundLine]

300 x 90

mm

Initialgauge length

with test area width 440 mm [AllroundLine]

5 to 250

mm

with test area width 640 / 1040 mm [AllroundLine]

5 to 240

mm

Measurement travel, max.

with test area width 440 mm [AllroundLine]

310 - initial gauge length

mm

with test area width 640 / 1040 mm [AllroundLine]

290 - initial gauge length

mm

Resolution at room temperature

0.5

µm

Resolution to ISO 9513 in ZwickRoell temperature chamber

at -20 to +250 °C

0.6

µm

at -40 °C

0.9

µm

at -55 °C

1.2

µm

Distance between extensometer reference plane and center of test axis:

table-top testing machine, test-area width 440 mm

450

mm

table-top/floor-standing testing machine, test-area width 640/1040 mm

570

mm

Image rate / measured-value acquisition rate, max.

500

fps / Hz

Max. test speed

1000

mm/min

Dimensions

Height

350

mm

Width

415

mm

Depth

140

mm

Specimen thickness

0 to 20

mm

Weight (incl. tunnel), approx.

15

kg

Accuracy class

to EN ISO 9513.

1

Scope of delivery

Measuring head with 3 digital cameras incl. 3 lenses and optical filter disc

Software for image acquisition and evaluation

Accessory case with alignment and marking aids

INC module (RS module for tC)

High-precision tests in temperature chamber

The operation of the testing machine including temperature control chamber is ergonomic and intuitive by the testing software. All components (material testing machine, extensometer and testing software) are from ZwickRoell.
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