Extensometers for Creep Compliance and Tensile Strength Testing of Asphalt – Model 39
  • 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.

  • • 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.
    • All standard units have linearity readings of 0.20% or better.
    • Includes high quality foam lined case.
    • Rugged, dual flexure design for improved performance.
    • Easy mounting, attaches with magnets, which allows dynamic testing to 40 Hz.

  • Gauge length adapters

    Gluing template for gage points

    Connectors to interface to nearly any brand test equipment

    Shunt calibration module 

  • 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 is -40℃ to +100℃ (-40°F to +210°F)

    Cable: Integral, flexible Teflon® cable, 2.5 m (8 ft) standard

    Operating Force: <30 g typical 

Designed to many of the needs for testing asphalt core samples in 4 and 6 inch diameters. The unit meets test method requirements for strain measurement developed under the U.S. Federal Highways SHRP program.
Gauge Lengths:
25-100 mm
Measuring Ranges:
±0.5 mm
Temperature Range:
-265℃ to 200℃ with -LHT option
Key Features: