Extensometers for materials testing

Extensometers for Creep Compliance and Tensile Strength Testing of Asphalt – Model 3910

Designed to many of the needs for testing asphalt core samples in 100 and 150 mm (4 and 6 inch) diameters. The unit meets test method requirements for strain measurement developed under the U.S. Federal Highways SHRP program.

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.

WITH EPSILON’S 20+ YEAR HISTORY OF SERVICE to the materials testing community, you know we will be there to stand behind our products when your critical application requires it.

36 EXTENSOMETER MODELS are available in many thousands of variations. Our focus on helping customers has led to the development of models to cover nearly any test method.

These extensometers are for creep compliance, tensile strength testing and dynamic resilient modulus testing. They are single integral, bi-axial units which measure both lateral and vertical deformations. They quickly clip onto gage points mounted per the test requirements. They mount much faster and easier than other types.

Two units are typically required, with one extensometer mounting to each side of the test specimen. They are changeable from the 1 inch centers used for 4 inch diameter specimens, to the 1.5 inch centers used for 6 inch diameter samples using optional gauge length adapters. Magnets at each end of the extensometer snap instantly in place on the steel gage points glued to the test sample. The quick attachment is most advantageous when testing pre-conditioned samples that are heated or cooled, since the extensometers can be mounted before the sample changes temperature appreciably.

The standard Model 3910 has full scale measuring range of 0.5 mm (0.020 inches). Gage points are included with the extensometers and optional gluing templates are available. This model can be converted to the Model 3909 with optional gauge length adapters.

The Model 3910 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.

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  • Model 3910 for creep compliance, resilient modulus, and tensile strength for testing per AASHTO T322.
  • Full bridge, 350 ohm strain gaged design for compatibility with nearly any test system.
  • Easy mounting, attaches with magnets, which allows dynamic testing to 40 Hz.
  • All standard units have linearity readings of 0.20% or better.
  • Includes the Epsilon Shunt Calibration System for on-site electrical calibration.
  • Rugged, dual flexure design for improved performance.
  • 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: ≤0.20% 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 Teflon® cable, 2.5 m (8 ft) standard

Operating Force: <30 g typical



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  • Gauge length adapters
  • Gluing template for gage points
  • Connectors to interface to nearly any brand of test equipment

Download Data Sheet  

Ordering Information

Click table options to configure

Gauge Length i

mm or inches #
25 mm -025M 025M
38 mm -038M 038M
50 mm -050M¹ 050M
76 mm -076M¹ 076M
100 mm -100M¹ 100M
1.000 in -0100 0100
1.500 in -0150 0150
2.000 in -0200¹ 0200
3.000 in -0300¹ 0300
4.000 in -0400¹ 0400

Model Number:  3910 – _ _ _

Model Number:

3910 – _ _ _

Model 3910 Available Versions: Available in intermediate and larger gauge lengths on special order. Other configurations may be available with special order; please contact Epsilon to discuss your requirements.

¹Special order only.

Example: 3910-0100: 1.000 inch gauge length with a full scale measuring range of 0.020 inches


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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Our 2018 Extensometer Catalog, Version 110 is now available! Not finding something you’re looking for? Ask us about a custom quote.