Phone: 719.694.8040
Fax:   888.809.3867




Our model EFSS high temperature axial extensometers are designed for testing metals, composites, and ceramics heated with a furnace or an induction heating system.

They feature a unique, co-axial, ceramic cord attachment system that is easier to mount and adjust and compatible with either furnaces or induction heating systems without requiring a different extensometer or configuration.

The ceramic attachment cords load the ceramic rods co-axially and apply the mounting force directly across the point of contact on the specimen. This greatly reduces the chance of the rods slipping on the specimen and signal errors due to rod deflection.

The mounting system also features simple, ceramic cords without the easily damaged hooks or spring tabs found in other designs. Contact force is adjustable via knurled thumb nuts and contact force can be adjusted even after the extensometer is mounted on the specimen .

With a full bridge, 350 ohm, strain gaged design, model EFSS is compatible with most test systems and signal conditioning electronics design 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.
  • Low profile Quick Attach System allows easy mounting to specimens in tight spaces.
  • Standard units meet ASTM class B-1 requirements for accuracy and a verification certificate is included with each unit.
  • Rugged, optimized, dual flexure design for strength and improved performance.
  • Replaceable, high purity alumina ceramic rod available in three contact tip styles: straight chisel, conical point, and vee chisel.
  • Includes spare ceramic rod set and a set of spare ceramic fiber cords.
  • For use up to 1200 °C (2200 °F) without cooling.
  • Connectors to interface to nearly any brand of test equipment.
  • Additional spare alumina ceramic rod available in three contact tip styles: straight chisel, conical point, and vee chisel.
  • Stand alone signal conditioners for use with DAQ boards or chart recorders.

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.

Temp. Range: Room temperature to 1200 °C (2200 °F)max.

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

Operating Force: Typically less than 20 g.

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

High Temperature Axial Extensometer - Model EFSS

Axial extensometer for high temperature tensile, compression, and cyclic testing using a furnace and induction heating system.  Gauge lengths from 10 to 50 mm (0.400" to 2.000") and full scale measuring ranges from 5% to 50% strain.

Unique Self-Supporting Design

adjustable mounting cords attach co-axially with the ceramic contact rods


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 EFSS high temperature axial extensometer is built with a modular design. This allows us to supply the exact gauge length and measuring range required for your test. Please contact us if your particular configuration is not listed.

Ordering Information: Model EFSS-____-____
Gauge Length:
Measuring Range:


100M = 10 mm

120M = 12 mm

125M = 12.5 mm

250M = 25 mm

0400 = 0.400 in

0500 = 0.500 in

0640 = 0.640 in

1000 = 1.000 in

1400 = 1.400 in

2000 = 2.000 in

0050 = ±5% strain

0100 = ±10% strain

0200 = +20% / -10% strain

0250 = +25% / -10% strain

0500 = +50% / -5% strain

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

Example: EFSS-250M-0100

(25 mm gauge length and ±10% measuring range)

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.