Phone: 719.694.8040
Fax:   888.809.3867




Our model EAA averaging axial extensometers and model EBA bi-axial extensometers are ideally suited for testing advanced composites and other anisotropic materials. They may also be used for general purpose tests and for determining Poisson's ratio.

With a unique, parallel flexure design, Reliant's bi-axial extensometers are designed for improved performance, reduced crosstalk, and rugged durability. They may be used with round or flat specimens and are easily adjustable to a variety of specimen widths / diameters.

The axial signal on both model EAA and EBA are usually wired for a single, averaged axial signal, but may be wired separately for two individual outputs.  This optional configuration is available if an indication of specimen straightness is required.

With a full bridge, strain gaged design, both model EAA and EBA are compatible with most test systems and signal conditioning electronics designed for strain gage based transducers. Reliant can provide stand-alone electronics to allow the use of data acquisition boards (DAQ), chart recorders or other test equipment.

  • May be left on through specimen failure.
  • 350 ohm, full bridge strain gaged design to ensure compatibility with most any test system.
  • Designed to measure in both tension and compression and can be used for cyclic testing.
  • Built-in mechanical over-travel stops provide protection in both directions.
  • Built-in Quick Attach System for self supported mounting on specimens.
  • Standard units meet ASTM class B-1 requirements for accuracy and a verification certificate is included with each unit.
  • Rugged, optimized, dual, parallel  flexure design for strength, improved performance, and reduced crosstalk.
  • Replaceable, tool steel knife edges and all units are shipped with a spare set.
  • High and low temperature options extend operation range from -270°C to +200 °C (-454 °F to +400 °F).
  • Connectors to interface to nearly any brand of test equipment.
  • Gauge length adapter kits.
  • Stand alone signal conditioners for use with DAQ boards.
  • High-Toughness, and specialty knife edges.

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

Output: 2 to 4 mV/V, nominal.

Linearity: ≤0.15% of full scale measuring range.

Standard Temp. Range: -40 °C to +100 °C (-40 °F to 210 °F) (optional temperature ranges available)

Cable: Standard 2.5 m (8 ft), ultra-flexible cable.

Quick Attach System: Fits round samples up to 25 mm (1.0 inch) diameter and flat samples up to 25 mm (1.000") wide.

Operating Force: Typically less than 50 g.

If you have any questions, please call or click request button below.

Averaging and Bi-Axial Extensometer - Model EAA / EBA

Averaged axial strain and transverse (lateral) strain in one integral unit. May be used for axial tensile, compression, and cyclic testing. Gauge lengths from 10 to 50 mm (and 0.400" to 2.000"), full scale measuring ranges of 5% or 10% strain, and temperature ranges from -270 °C to 200 °C.

Unique and Robust, Parallel Flexure Design

optimized for high linearity, performance, and ruggedness


ASTM E83 and ISO 9513

designed and verified to meet current standards


Over 10 Years Serving the Industry

we will be there with service and support when you need it


Our model EAA and EBA extensometers are built with a modular design. This allows us to supply the exact gauge length, measuring range, and temperature range required for your test. Please contact us if your particular configuration is not listed.

Ordering Information: Model EA_-____-____-_
Gauge Length:
Measuring Range:
Temperature Range:



100M = 10 mm

125M = 12.5 mm

250M = 25 mm

500M = 50 mm

0040 = 0.400 in

0050 = 0.500 in

0100 = 1.000 in

0200 = 2.000 in

050M = ±5% axial / ±0.5 mm transverse

100M = ±10% axial / ±1 mm transverse

050T = ±5% axial / ±0.0250" transverse

100T = ±10% axial / ±0.050" transverse

S = -40 °C to +100 °C

L = -270 °C to +100 °C

H = -40 °C to +200 °C

X = -270 °C to +200 °C

Model EAA and EBA is available in almost any configuration of gauge length, measuring range and temperature range listed above. Other configurations are available; please contact Reliant with your requirements.

Example: EBA-100M-100M-S

(Model EBA, 10 mm gauge length, ±10% axial / ±1 mm transverse measuring range, and standard temperature option)

Reliant Technology LLC.

2334 E Boulder Street

Colorado Springs, CO 80909 USA


Questions or Repair?

If you have any questions or would like a quote, please contact us HERE.

If your extensometer is in need of service or repair, please fill out an RMA form HERE.