laserXtens Extensometer

The laserXtens is a non-contact extensometer that performs tests with the highest accuracy, without the need for gauge marks.

As a special development, the laserXtens stands out in the range of non-contact extensometers. It does not require specimen markings. The specimen is illuminated with laser light and the reflected laser beams generate a speckle pattern in the camera. The process is highly accurate and offers a wide range of evaluation options. Since no specimen marking is required, a lot of time is saved. 
laserXtens Array HP extensometer

Applications

Extensometers from the laserXtens systems series measure without contact and with the highest level of accuracy. The measuring principle eliminates the need to apply gauge marks. This allows the laserXtens systems to be used for a wide range of applications:

  • Tensile, flexure and compression testing preferably on metals or other materials that disperse the laser light on the surface.
  • Testing on contact-sensitive specimens or specimens with high fracture energy.
  • Highly accurate testing in temperature chambers and high-temperature testing
  • Applications in which more than two measuring points are used, e.g. biaxial deformation measurements or strain distribution.
  • Measurements on small specimen geometries or components.

Due to its flexibility and easy handling the laserXtens is ideal for applications in the field of quality assurance, as well as in research and development.

Key Advantages and Features

Testing without specimen marking

  • Testing without specimen marks
  • laserXtens' unique technology eliminates the need for specimen marking.
  • Significant time and cost savings, particularly with high specimen throughput.
  • The advantages are especially apparent with options covering multiple measuring points or entire specimen surfaces.
  • Easy to use in temperature chambers, where environmental conditions can make gauge mark application really difficult.
  • Ideal for automated systems - no manual specimen preparation required.

Simple operation

  • Easy operation
  • Tamper-proof: The housing of the complete systems are lacquered; nothing can be adjusted on the lenses. This is an important requirement for reliable test results.
  • Simple alignment to the specimen: Through the connection to the crosshead, the laserXtes is aligned centrally to the gauge marks. This can be done very quickly due to the ease of height-adjustment. (not for laserXtens 1-15 HP).
  • Compensation of various specimen thicknesses and testing of shear specimens.
  • Wear-free system, and as a result also low-maintenance. The systems have an extremely long service life.

High accuracy

  • High accuracy down to the last detail
  • laserXtens possesses high precision in the micro and macro measurement ranges.
  • ZwickRoell extensometers exceed the requirements of the standards and are calibrated over the entire measurement range to Accuracy Class 0.5, ISO 9513.
  • Calibration in Accuracy Class 0.5 to ISO 9513 with first calibration point from as early as 20 µm.
  • Industrial-quality cameras and high-quality, low-distortion lenses.
  • Specimens from 1 mm in width/diameter can be tested; even smaller specimens may be possible following pre-testing.
  • In contrast to contact-type extensometers or pure video instruments, laserXtens can measure strain on short specimens (gauge lengths from 3 mm) with high accuracy.
  • Extensometer mounted using stable, low-vibration mounting arms.
  • Housing provides protection against dirt and dust and inadvertent loss of adjustment of components.
  • Exact synchronization of all measurement channels.
  • A tunnel minimizes environmental influences such as air currents.

Automatic centering

  • Automatic centering increases measurement travel and measuring accuracy.
  • laserXtens 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.
  • This results in increased system accuracy; the gauge marks shift less in the image and are captured in the (more accurate) center of the lens.
laser_7-220HP_ImageArticle

laserXtens 7-220 HP

The laserXtens 7-220 HP extensometer features seven fixed high-resolution cameras and five laser light sources. The overlapping fields of view of the seven cameras are pooled into one large picture. Both virtual gauge marks are also tracked here during the loading process (speckle tracking). If a gauge mark makes hits the edge of a camera’s field of view, it will be transferred to the field of view of the adjacent camera. This method results in a large measurement range with high resolution.

Combined overall image of the specimen

Typical application laserXtens 7-220 HP

Sheet metals and flat steel to ISO 6892-1

  • Specific advantages for this application:
  • Strain-rate controlled tests to ISO 6892-1 Method A1 (closed loop) (for gauge lengths ≥ 30 mm).
  • Determination of strain at break, including specimens with high fracture energy - no damage due to hard impacts at break.
  • No specimen marking required, therefore significant time saving.
  • No specimen is wasted due to breaks outside L0: the strain distribution option automatically sets L0 around the area of highest strain and the break location.
  • Second measurement axis option: determination of change in width and r-value to ISO 10113.
  • Width measurement always centered: the extensometer tracks via connection to the crosshead. This results in a larger measuring range and the system is automatically positioned centrally to the gauge length at all times.
  • High-accuracy testing in the ZwickRoell temperature chamber: temperature control and air distribution in the temperature chamber are optimized so that the laserXtens resolution is only minimally affected, even at temperature.
  • 2D dot matrix option: measurements over the entire specimen, at different measuring points.
  • The laserXtens 7-220 HP has no moving parts and is completely wear-free.
  • Patented unrivaled array technology.
  • Resistant to environmental influences (e.g. air currents); the flexible tunnel minimizes signal interference.
laserXtens_2-220HP

laserXtens 2-220 HP

The measuring head of the laserXtens 2-220 HP consists of two digital cameras that are mounted to motorized carriages. This enables the distances between the cameras to vary and thus different initial gauge lengths to be implemented.
The laserXtens 2-220 HP is suitable for use with temperature chambers.
Additionally, the laserXtens 2-220 HP can be used for for strain-rate controlled tests to ISO 6892-1 Method A1 “Closed Loop” (for gauge lengths ≥ 50 mm).

Typical application laserXtens 2-220 HP

Sheet metals and flat steel to ISO 6892-1

  • Specific advantages in this application
  • Strain-rate-controlled tests to ISO 6892­1 Method A1 (closed loop) (for gauge lengths ≥ 50 mm) are used.
  • Determination of strain at break, including specimens with high fracture energy - no damage due to hard impacts at break.
  • No specimen marking required - significant time saving.
  • Second Measurement Axis option: determination of change in width and r-value to ISO 10113.
  • Width measurement always centered: 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.
  • Optional temperature chamber or connection for testing at high temperature.
  • High-accuracy testing in the ZwickRoell temperature chamber: temperature control and air distribution in the temperature chamber are optimized so that laserXtens resolution is only minimally affected, even at temperature.
  • Resistant to environmental influences (e.g. air currents); flexible tunnel minimizes signal interference.
laserXtens_1-15 HP_+FO

laserXtens 1-15 HP

The laserXtens 1-15 HP is a high-accuracy testing system for testing small and very small specimens. Therefore, in addition to a camera and two laser light sources, it also has a special lens. This is because a telecentric lens can compensate for lateral specimen movements (see below).

Due to the short distance to the specimen, this laserXtens can be mounted only to the zwickiLine. It is not moved; it has no connection to the crosshead.

laserXtens 1-15 HP: Compensating for lateral specimen movements
With some specimens or test arrangements, the specimen is prone to moving out of the test axis. This is especially common with small specimens. A change in the specimen distance to the camera does however, in a trapezoidal field of view, result in an magnification/demagnification of the specimen, whereby the test results are influenced. The telecentric lens of the laserXtens 1-15 HP compensates for these lateral specimen movements and minimizes measurement error.

Typical application laserXtens 1-15 HP

Mini and micro specimens: stents, fine wire, mini metal specimens

  • Specific advantages in this application
  • Contact-type systems cannot be used for these as they are unable to access the specimen.
  • No influence on the specimen - no contact, no specimen marking.
  • Out-of-plane movement compensated for by telecentric lens.
  • Resolution: 0.04 µm - no comparable system for micro specimens.
  • Accuracy Class 0.5
  • Time-saving - no specimen marking required.
  • Our competitors have no comparable product with laser speckle technology.
  • Customizing - can be connected to special temperature chambers to test sensitive specimens at uniform temperature.
  • laserXtens 1-15 HP has no moving parts and is completely wear-free.
  • Option: 2D dot matrix over the entire specimen, at different measuring points or whole surface.
High Temperature Furnace with laserXtens 2-120 HP/TZ

laserXtens 2-120 HP/TZ

The laserXtens 2-120 HP/TZ provides non-contact measurement of deformations on a range of materials in varying environmental conditions up to 2,000°C. The laserXtens 2-120 HP/TZ is equipped with two cameras, two green laser light sources for measurement at very high temperatures, and two telecentric lenses. The telecentric lenses make the laserXtens 2-120 HP/TZ resistant to distance changes between the lens and specimen. When using the laserXtens 2-120 HP/TZ in connection with temperature chambers and high temperature furnaces, the negative influence on the measurement signal due to changed optical conditions such as air currents, must be taken into consideration. With the laserXtens 2-120 HP/TZ these influences are minimized by means of an optical tunnel.

Typical application laserXtens 2-120 HP/TZ

Metals to ISO 6892-2

  • Specific advantages for this application:
  • Strain-rate controlled tests to ISO 6892-2 (high temperature) and to ISO 6892-1 (room temperature) Method A1 (closed loop).
  • Measurement of transverse strain and deflection without additional markings and without required hardware expansion (software option).
  • The adjustment of different gauge lengths is motor-driven.
  • The specimen is not affected by the laser light.
  • Even at elevated temperatures, sensitive specimens are not affected by the extensometer.
  • Sensor arms are maintenance-free and not prone to breaking.
  • Resistant to environmental influences (e.g. air currents); the flexible tunnel minimizes signal interference.
  • Temperature chambers and high temperature furnaces can remain completely closed. Openings are thermally sealed with glass windows.
  • Specimen markings are not required, saving time especially with high specimen throughput, as for example in the case of carousel solutions.
laserXtens 1-32 HP/TZ

laserXtens 1-32 HP/TZ

The laserXtens 1-32 HP/TZ includes one camera, two green laser light sources for measurement at very high temperatures, and one telecentric lens for reduction of distance changes between the lens and specimen. The measuring principle eliminates the need to apply gauge marks.

The laserXtens 1-32 HP/TZ is intended for use with vacuum chambers, furnaces, and induction up to a temperature range of +2,000°C.

When using the laserXtens 1-32 HP/TZ in connection with temperature chambers and high temperature furnaces, it must be taken into consideration that the measurement signal may be negatively influenced due to changed optical conditions such as air currents. These influences are minimized by means of an optical tunnel.

Typical application laserXtens 1-32 HP/TZ

Metals to ISO 6892-2

  • Specific advantages for this application:
  • Strain-rate controlled tests to ISO 6892-2 (high temperature) and to ISO 6892-1 (room temperature) Method A1 (closed loop).
  • Measurement of transverse strain and deflection without additional markings and without required hardware expansion (software option).
  • Different gauge lengths can be set in fractions of a second.
  • The specimen is not affected by the laser light.
  • Even at elevated temperatures, sensitive specimens are not affected by the extensometer.
  • Sensor arms are maintenance-free and not prone to breaking.
  • Resistant to environmental influences (e.g. air currents); the flexible tunnel minimizes signal interference.
  • Temperature chambers and high temperature furnaces can remain completely closed. Openings are thermally sealed with glass windows.
  • Specimen markings are not required, saving time.

Software Options 

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

Test re-run

The optional Test ReRun module enables subsequent recalculation of strain on the basis of an image series recorded during a test, using a different initial gauge-length (provided multiple markings 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.

Automatic symmetrical adjustment of strain around necking to ISO 6892-1, Annex I

The recalculated strain can, of course, be synchronized subsequently with the other measurement values via the testXpert testing software.

Strain distribution

The Strain Distribution option enables determination of local strains at multiple measuring locations along the specimen gage-length. Evaluation of up to 16 measuring locations is possible. This option also allows automatic real-time symmetrical adjustment of the initial gage-length around the necking (as per ISO 6892-1, Annex I).

Video Capturing

Extension measurement with the non-contact laserXtens

Measuring completely without measuring marks and with highest precision

laserXtens Extensometer

Ideal for tensile tests, compression tests and bending tests on metals, plastics, components; at room temperature and under temperature.

Technical data

laserXtens 7-220 HP

Type

laserXtens 7-220 HP

Item No.

1043974

Initial gauge length

3 ... 200

mm

Measurement travel with speckle tracking

210 mm - initial gauge length

Measurement travel for flow measurement

After measurement travel via speckle tracking, laserXtens switches to flow measurement.

Strain rate control to ISO 6892-1 Method A1

From 30[1]

mm

Resolution

0.07

µm to EN ISO 9513

Accuracy class

To EN ISO 9513

0.5

To ASTM E83

B2

Field of view, FOV (L x W)

220 x 28

mm

Typical measurement frequency (adjustable)

70

Hz

Measurement speed, max. at the measuring point

500

mm/min

Specimen dimensions

Flat specimen, thickness

1 ... 30

mm

Round specimen, Ø

1 ... 30

mm

Dimensions:

Height

460

mm

Width

485 ... 745

mm

Depth

140

mm

Minimum version

testXpert II V 3.71 and testXpert III

Laser safety class to DIN EN 60825-1 (11-2001)

2[2]

Scope of delivery:

Measuring head with seven high resolution digital cameras including lenses, five red laser light sources, tunnel for minimizing signal interference, INC module (for tC: RS module), software license, accessory case with scale aid.

  1. Not in temperature chamber
  1. No safety measures required.

laserXtens 2-220 HP

Type

laserXtens 2-220 HP

Item No.

1043978

Initial gauge length

3 ... 200

mm

Measurement displacement with speckle tracking

  • Initial gauge length: 3 ... 25 mm; max. measured displacement: 25 mm - initial gauge length (measurement with camera)
  • Initial gauge length: 20 ... 180 mm; max. measured displacement: 50 mm
  • Initial gauge length: 180 ... 200 mm; max. measured displacement: 220 mm - initial gauge length

Measurement displacement for flow measurement

After measurement displacement via speckle tracking, laserXtens switches to flow measurement.

Strain rate control compliant to ISO 6892-1 Method A1

from 50[1]

mm

Resolution

0.07

µm to EN ISO 9513

Accuracy class

To EN ISO 9513

0.5

According to ASTM E83

B2 from gauge length 15 mm

Typical measurement frequency (adjustable)

70

Hz

Measurement speed, max. at the measurement point

500

mm/min

Specimen thickness

Flat specimens, measured on the broad side

≤30

mm

Flat specimens, measured on the specimen edge

>1[2]

mm

Round specimens

1 ... 30[2]

mm

Dimensions:

Height

460

mm

Width

485 ... 745

mm

Depth

140

mm

Ambient temperature

+10 ... +35

°C

Minimum version

testXpert II V 3.71 / testXpert III

Laser safety class to DIN EN 60825-1 (11-2001)

2[3]

Scope of delivery

Measuring head with motorized gauge length adjustment (automatic L0 setting), 2 digital cameras including lenses F=75mm, 2 red laser light sources, software for image acquisition, evaluation of the cross correlation and transfer to testXpert III, accessory case with scale aid.

  1. Not in ZwickRoell temperature chamber
  1. Pre-tests are required for specimens with a specimen thickness < 1 mm.
  1. No safety measures required.

laserXtens 1-15 HP

Type

laserXtens 1-15 HP

Item No.

1043981

Initial gauge length

3 ... 14

mm

Measurement displacement with speckle tracking

15

mm - initial gauge length

Measurement displacement for flow measurement

After measurement displacement via speckle tracking, laserXtens switches to flow measurement.

Resolution

0.04

μm to EN ISO 9513

Accuracy class

To EN ISO 9513

0.5

According to ASTM E83

W2

Typical measurement frequency (adjustable)

70

Hz

Measurement speed, max. at the measurement point

250

mm/min

Specimen thickness

Flat specimens

≤30

mm

Round specimens

0.5 ... 30[1]

mm

Dimensions

Height

175

mm

Width

306

mm

Depth

91

mm

Ambient temperature

+10 ... +35

°C

Laser safety class to DIN EN 60825-1 (11-2001)

2[2]

Scope of delivery

Measuring head with one digital camera including telecentric lenses, two red laser light sources, software for image acquisition, evaluation of the cross correlation and transfer to testXpert III, accessory case with scale aid

  1. Pre-tests are required for specimens with a specimen diameter < 1 mm.
  1. No safety measures required.

laserXtens 2-120 HP/TZ

Type

laserXtens 2-120 HP/TZ

Laser safety class to DIN EN 60825-1 (11-2001)

2[1]

Initial gauge length

Measurement with one camera

1.5 ... 25

mm

Measurement with two cameras

25 ... 120

mm

Measured displacement with speckle tracking[2]

1.5 ... 25 mm

32 mm - initial gauge length

25 ... 120 mm

30 mm (for fixed assembly)

60 mm (for automatic entrainment)

Measurement displacement flow measurement

After reaching the max. measurement displacement, switch to flow measurement mode

Resolution

0.11

µm

Accuracy class to EN ISO 9513

0.5

Temperature range

-150°C ... +2,000°C

Measurement frequency for standard setup

70

Hz

Max. measurement speed at measurement point

500

mm/min

Scope of delivery

Measuring head with motorized gauge length adjustment (automatic L0 setting), two digital cameras incl. high resolution telecentric lenses, two green laser light sources, high temperature tunnel for reduction of environmental influences, software for image acquisition, evaluation of cross-correlation and transfer to testXpert II (Version 3.71 or higher) or testXpert III, accessory case with scaling aid, INC module (for tC: RS module). Incl. connection to crosshead; the extensometer tracks at half test speed.

  1. No protective measures required.
  1. If necessary, restriction implemented via furnace or temperature chamber

laserXtens 1-32 HP/TZ

Type

laserXtens 1-32 HP/TZ

Laser safety class to DIN EN 60825-1 (11-2001)

2[1]

Initial gauge length

1.5 … 25

mm

Measured displacement with speckle tracking[2]

For fixed assembly

32 mm - initial gauge length

For automatic entrainment

2 * (32 - initial gauge length)

Measurement displacement flow measurement

After reaching the max. measurement displacement, switch to flow measurement mode

Resolution

0.11

µm

Accuracy class to EN ISO 9513

0.5

Temperature range

-150°C ... +2,000°C

Measurement frequency for standard setup

70

Hz

Max. measurement speed at measurement point

500

mm/min

Scope of delivery

Measuring head with one digital camera incl. high resolution telecentric lens, two green laser light sources, high temperature tunnel for reduction of environmental influences, software for image acquisition, evaluation of cross-correlation and transfer to testXpert III, accessory case with scaling aid, INC module (for tC: RS module). Incl. connection to crosshead; the extensometer tracks at half test speed.

  1. No protective measures required.
  1. If necessary, restriction implemented via furnace or temperature chamber

High-accuracy testing in the temperature chamber

The testing machine including temperature chamber features convenient, intuitive operation via the testing software. All components (materials testing machine, extensometer, and testing software) are developed in-house at ZwickRoell.
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