Extensometers for materials testing

Axial Extensometer – Model 3542

General purpose strain gage extensometers for axial tensile, compression, and cyclic testing. Gauge lengths from 10 to 80 mm (and 0.5 to 2 inches) and full scale measuring ranges from 5% to 100% strain.


provides higher measuring ranges with much shorter extensometer arm lengths – all with much greater low strain performance.


to the materials testing community, you know we will be there to stand behind our products when your critical application requires it.

Operation of these, and all of Epsilon’s extensometers, are


using in-house calibration systems that are calibrated with Epsilon’s laser interferometer system.

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

They come standard with Epsilon’s quick attach kit, making it possible to mount the extensometer on the test specimen quickly and easily with one hand. The quick attach kit can be removed, allowing mounting of the extensometer with springs or rubber bands.

Model 3542 extensometers are applicable for testing with the following standards:
• ISO 6892-1, 527-2, 527-4, 527-5, 10113
• ASTM E8, E9, D3039, D638, A370, D3552, E517, E646

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, Epsilon can provide a variety of solutions, allowing the extensometer output to be connected to data acquisition boards, chart recorders or other equipment.

For gauge lengths 100 mm (4 inches) or greater see Model 3542L.

Download Data Sheet


  • May be left on through specimen failure.
  • All models can measure in both tension and compression and can be used for cyclic testing.
  • Standard quick attach kit allows one hand mounting to specimens.
  • Standard units meet ASTM class B-1 requirements for accuracy. A test certificate is included. ISO 9513 class 0,5 test certificates are available upon request.
  • Includes the Epsilon Shunt Calibration System for on-site electrical calibration.
  • Rugged, dual flexure design for strength and improved performance. Much stronger than single flexure designs, this also allows cyclic testing at higher frequencies.
  • All models have mechanical overtravel stops in both directions. Cable stops are used for overtravel protection where required. Epsilon’s cable stops are fully contained between the arms of the extensometer and do not hang below where they can interfere with fixturing–especially during compression testing.
  • Hardened tool steel knife edges are easily replaced. A spare set comes with every extensometer.
  • Replaceable arms and spacers for ease of repair. This also allows changing the gauge length for different test requirements.
  • High and low temperature options extend operation from as low as -270°C to +200 °C (-454 °F to +400 °F).
  • Full bridge, 350 ohm strain gaged design for compatibility with nearly any test system.
  • Includes high quality foam lined case.

Download Data Sheet




Excitation: 5 to 10 VDC recommended, 12 VDC or VAC max.

Output: 2 to 4 mV/V, nominal, depending on model

Linearity: ≤0.15% of full scale measuring range

Temperature Range: Standard (-ST) is -40 °C to +100 °C (-40 °F to 210 °F)

Cable: Integral, ultra-flexible cable, 2.5 m (8 ft) standard

Standard Quick Attach Kit: Fits round samples up to 25 mm (1.0 inch) diameter and flats up to 12 mm thick by 31 mm wide (0.5 inch by 1.25 inch); attach to larger specimens using rubber bands or springs (included)

Operating Force: 30 g typical



Download Data Sheet


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

Download Data Sheet



Product Videos

Metal tension test with axial extensometer

Quick Attach demonstration

Ordering Information

Click table options to configure

Gauge Length i

mm or inches #
10.0 mm -010M 010M
12.0 mm -012M 012M
12.5 mm -0125M 0125M
25.0 mm -025M 025M
50.0 mm -050M 050M
80.0 mm -080M 080M
0.500 in -0050 0050
0.640 in -0064 0064
1.000 in -0100 0100
1.400 in -0140 0140
2.000 in -0200 0200

Measuring Range¹ i

% strain #
±5% -005² 005
±10% -010 010
+20%/-10% -020 020
+25%/-10% -025 025
+50%/-10% -050 050
+100%/-10% -100 100

Temperature Range

degrees #
-270 °C to 100 °C (-454 °F to 210 °F) -LT LT
-40 °C to 100 °C (-40 °F to 210 °F) -ST ST
-40 °C to 150 °C (-40 °F to 300 °F) -HT1 HT1
-40 °C to 200 °C (-40 °F to 400 °F) -HT2 HT2
-270 °C to 200 °C (-454 °F to 400 °F) -LHT LHT

Model Number:  3542_ _ _ __ _ __ _

Model Number:

3542_ _ _ __ _ __ _

Model 3542 Available Versions: ANY combination of gauge length, measuring range and temperature range listed above is available, except as noted. Other configurations may be available with special order; please contact Epsilon to discuss your requirements.

¹Compressive ranges can be adjusted to higher values if required. Please contact Epsilon for your specific testing requirement.
²Not available in 10 mm, 12.5 mm, or 0.50 inch gauge lengths.

Example: 3542-010M-020-LT: 10.0 mm gauge length, +20%/-10% measuring range, low temperature option (-270 °C to 100 °C)

Download Product Guide

Axial and High Temperature

Shunt Calibration

SCM Shunt Calibration Modules

Knife Edge Options

Available for Epsilon Extensometers


If your unit is in need of service, calibration or repair, initiate the RMA process with us and we will be happy to assist.

Get Our Newsletter

Sign up for our newsletter to get the most up-to-date information on products and services.

Download Catalog

2017 Extensometer Catalog, Version 109 is now available! Not finding something you’re looking for? Ask us about a custom quote.