Long Gauge Length Axial Extensometers – Model 3542L

Long gauge length extensometers with gauge lengths 100 mm (4 inches) or greater for tensile and compression testing. These units are for long gauge length applications where low-level strain measurements such as offset yield are required.

Epsilon extensometers are COMPATIBLE WITH VIRTUALLY EVERY BRAND OF TEST EQUIPMENT and can be supplied with the correct connector to plug in directly, or supplied with a separate conditioner and amplifier.

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


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


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

The dual flexure design makes the 3542L very rugged and insensitive to vibrations. These extensometers are designed for testing a wide range of materials including metals, plastics, composites and ceramics. Epsilon’s Model 3543 is recommended for applications requiring long gauge lengths and larger measuring ranges.

The Model 3542L comes standard with Epsilon’s quick attach kit, making it easy to mount the extensometer on the test specimen. The quick attach kit can be removed, allowing mounting of the extensometer with springs or rubber bands.

Model 3542L 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 with electronics for a strain channel, and Epsilon will equip the extensometer with a compatible connector that is wired to plug directly into the controller. For systems lacking the required electronics, Epsilon can provide a variety of signal conditioning solutions that enable connecting to data acquisition systems or other equipment.

For gauge lengths less than 100 mm (4 inches), see Model 3542.

Download Data Sheet

  • May be left on through specimen failure in most applications.i
  • 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.
  • Standard quick attach kit allows quick mounting to specimens.
  • 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 -270 °C (-454 °F) to +200 °C (400 °F).
  • Replaceable arms and spacers for ease of repair. This also allows changing the gauge length for different test requirements.
  • 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.
  • 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

Accuracy: Standard configurations meet ASTM E83 class B-1 and ISO 9513 class 0,5 requirements for accuracy. A test certificate is included.

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:
Wireforms are included for round samples up to 25 mm diameter (1.0 inch) and flats to 12 mm thick by 31 mm wide (0.5 inch by 1.25 inch); wireforms are available for many other specimen sizes – contact Epsilon

Operating Force: Depends on model configuration, less than 30 g typically



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

Ordering Information

Click table options to configure

Gauge Length i
mm or inches #
100 mm -100M 100M
150 mm -150M 150M
200 mm -200M 200M
250 mm -250M 250M
500 mm -500M 500M
600 mm -600M 600M
4.000 in -0400 0400
6.000 in -0600 0600
8.000 in -0800 0800
10.000 in -1000 1000
20.000 in -2000 2000
24.000 in -2400 2400
Measuring Range i
extension #
±2.5 mm -0025M 0025M
±6.0 mm -006M 006M
+12.5/-6.0 mm -0125M 0125M
+25.0/-6.0 mm -025M 025M
±0.10 in -010T 010T
±0.25 in -025T 025T
+0.50/-0.25 in -050T 050T
+1.00/-0.25 in -100T 100T


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: 3542L – _ _ _ __ _ _ __ _

Selected Tensile Measuring Range: _ _ _ _

Model 3542L 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.

Example: 3542L-200M-0125M-ST: 200 mm gauge length, +12.5 / -6.0 mm measuring range, standard temperature option (-40 °C to 100 °C)


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

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