Product Catalogue/Brochure

PLAST Electronic Extensometer
Axial Extensometers
Laser Extensometer

Extension measurement is one of the areas that complements our range of UTM program. The result is a comprehensive range of high class variations. The product selection is arranged as follows:

  • Non-contact extensometers with and without measurement marks.
  • Contact extensometers: Sensor arm extensometers, incremental and analogue clip-on extensometers as well as extensometers for compression and flexure tests.

PLAST Electronic Extensometer

  • Suitable to measure the longitudinal deformation of the specimens up to rupture
  • Particularly suitable for material with high elongation  plastics, fabrics, rubbers and elastometers
  • Automatic opening and closing of the knives by pneumatic control
  • Adjustable force of the knives closing
  • Pressure regulator
  • Interchangeable knives:
    • cusp  (standard)
    • coated in high adhesion rubber REF:
  • Frontal specimens loading
  • Measure of the bi-directional deformation in case of oligocyclic tests
  • Device for extensometer rotation for the positioning of the arms out of the machine overall dimension
  • Low initial mass with min. activation of static and dynamic forces
  • A 6 bar compressed air feeding is required
  • For testing instruments with nominal force up to 50kN it is necessary to foresee a delivery pipe Ø 4 mm and filtered air.

Axial Extensometers 3542-Line

Model 3542 Axial Extensometers

General purpose extensometers for axial tensile, compression and cyclic testing. Gage lengths from 0.5 to 2 inches (and 10 to 50 mm) and measuring ranges from 5% to 100% strain.

These extensometers are designed for testing a wide range of materials, including metals, plastics, composites and ceramics. All will work in both tension and compression. The dual flexure design makes them very rugged and insensitive to vibrations, which permits higher frequency operation.

They come standard with Qualitest’s quick attach kit, making it easy to mount the extensometer on the test specimen in seconds with one hand. The quick attach kit can be removed, allowing mounting of the extensometer with springs or rubber bands.

The Model 3542 extensometers are strain gaged devices, making them compatible with any electronics designed for strain gaged transducers. Most often they are connected to a test machine controller. The signal conditioning electronics for the extensometer is typically included with the test machine controller or may often be added. In this case the extensometer is shipped with the proper connector and wiring to plug directly into the electronics. For systems lacking the required electronics, Qualitest can provide a variety of solutions, allowing the extensometer output to be connected to data acquisition boards, chart recorders or other equipment.


  • May be left on through specimen failure.
  • Full bridge, 350 ohm strain gaged design for compatibility with nearly any test system.
  • All models can measure in both tension and compression and can be used for cyclic testing.
  • Mechanical overtravel stops in both directions.
  • Most standard units meet existing ASTM class B-1 and ISO 9513, class 0,5 requirements for accuracy.  Measuring ranges greater than 50% will meet these class requirements in lower calibration ranges.
  • Hardened tool steel knife edges are easily replaced. A spare set comes with every extensometer.
  • High and low temperature options extend operation from as low as -265 °C (-450 °F) to +200 °C (400 °F).
  • Includes high quality foam lined case.
  • Replaceable arms and spacers for ease of repair. This also allows changing the gage length for different test requirements.
  • Rugged, dual flexure design for strength and improved performance. Much stronger than single flexure designs, this also allows cyclic testing at higher frequencies.
  • Standard quick attach kit allows one hand mounting to specimens.


  • Excitation: 5 to 10 VDC recommended, 12 VDC or VAC max.
  • Output: 2 to 4 mV/V, nominal, depending on model
  • Linearity: 0.10% to 0.15% of full scale measuring range, depending on model
  • Temperature Range: Standard (-ST) is -40 °C to +100 °C (-40 °F to 210°F)
  • Cable: Integral, ultra-flexible cable, 8 ft (2.5 m) standard
  • Standard Quick Attach Kit: Fits round samples up to 1.0 inch diameter (25 mm) and flats to 0.5 inch thick by 1.25 inch wide (12 mm by 31 mm)
  • Operating Force: 30 g typical


  • Quick attach kit wireforms for large specimens
  • Adapter kits to change gage lengths
  • Connectors to interface to nearly any brand test equipment
  • Special coatings and stainless steel knife edges available for biomedical tests.

Laser Extensometer LE-5

The LE Model Laser Extensometers are precision, wide-range instruments specifically designed for accurate, non-contact measurement of strain on various materials under tensile or compressive conditions. They may also be utilized for other applications where non-contact measurement is desired. The LE models are completely self-contained and are housed in a single compact enclosure. They take advantage of the latest laser technology in order to achieve high performance with minimal maintenance.

The Model LE Laser Extensometers provide: a digital display; 4 button keypad; analog output; and an RS-232 computer interface; all of which are located on the back panel. Instrument operation may be from the back panel or remote via the RS232 interface.
Although these instruments are designed to handle a wide range of measurement applications, the Model LE Laser Extensometers are easy to operate. They utilize a unique scanning laser beam technique to measure dimension changes from one side of the subject, eliminating the need for a scan receiver on the opposite side. For special applications requiring transmission around or through a specimen or other object, alternate methods can be implemented.

The LE Laser Extensometers are normally operated with the beam in a vertical plane but they can be operated in other planes as well. Target materials are available for various measurement applications.



Measurement Range

0.3-5.0 in. (8-127 mm)
± 0.0004 in. (±0.010 mm)
0.0001 in. (0.001 mm)


±0.0002 in. (±0.005 mm)
15" x 7.1" x 4.5"
13 lb. (6 kg)

System units:
Analog Output Ranges

2 line, 16 character/line, LCD Display with LED backlighting
In. or mm, selectable
16 bit, selectable range, ±10V full scale
0.1 , 0.2 , 0.5 , 1.0 , 2.0 , 5.0 ,10.0 , 20.0 inch full scale
2.0 , 5.0 , 10.0 , 20.0 , 50.0 , 100 , 100 , 500 mm full scale

Target Distance

10 in. nominal, 20 in. maximum, selectable
250 mm nominal, 500 mm maximum, selectable

Scan Rate

100 scans/second

Multiple Scan Averaging

A moving window average is applied over a selectable number of scans to digitally filter the output reading.

RS232 I/O Port
Zero Suppression
Laser Source

Standard 3-wire type, selectable Baud rate (9600, 4800, 2400, 1200)
Reading can be zeroed anywhere within the full scale range of the instrument
670nm diode laser; <1mW maximum scanned output;
CDRH certified class II laser instrument

Power Input

115 VAC ±10%, 50/60 Hz (standard), 230 VAC ±10%, 50/60 Hz (optional)
Four 1/4-20 mounting holes in base

*Over optimum displacement range at calibrated target distance
Note: Specifications measured at 25 deg. C, 50% relative humidity. These specifications are typical and subject to change without notice.


For more information about Extensometers, please call us at 1.877.884.8378 or Click the button below.