3580 High Temperature Diametral Extensometers for Strain Measurements at Temperatures to 1000 °C

Epsilon’s 3580 extensometers are used for transverse or diametral strain measurements at temperatures up to 1000 °C (1832 °F). These extensometers can be used with induction heating systems or with furnaces with a side entry slot for an extensometer. They have a proprietary, rugged dual flexure design.

The Model 3580 extensometer is used for diametral strain measurement with furnace and induction heating systems. Water-cooling and quartz rods allow the unit to be used for high temperature testing of ceramics, metals and composites. For induction heating, this model can often be used without water-cooling.

These extensometers are often mounted directly to the side cut-out when used in furnaces. In cases where furnace mounting is not possible, optional load frame mounting brackets are available to support the extensometer. These optional mounts are used with furnace systems or induction heating.

The Model 3580 extensometers are strain gaged devices and this makes them compatible with any electronics designed for strain gaged transducers. Often, they are connected to a test machine controller. The signal conditioning electronics for the extensometer is usually included with the test machine controller or may often be added.

In this case, the extensometer is delivered with the right wiring or connector to plug directly into the electronics. Epsilon can provide a range of solutions for systems that do not have the required electronics and allows the extensometer output to be connected to chart recorders, data acquisition boards or other equipment.

Epsilon extensometers are compatible with almost 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.

The company has over 20 years history of service for the materials testing community, and will be there to stand behind their products when the user’s critical application requires it.

Epsilon offers 36 Extensometer Models in numerous variations and their focus on helping customers has led to the development of models to cover virtually any test method.


The key features of the Model 3580 extensometers are as follows:

  • Full bridge, 350 ohm strain gaged design for compatibility with nearly any test system
  • All standard units have linearity readings of 0.15% or better
  • Each unit comes with a spare set of quartz rods, universal water-cooled mounting bracket and a foam lined storage case
  • Suitable for measuring Poisson’s ratio per ASTM E132 with most materials and specimens
  • Rugged, dual flexure design for strength and improved performance. Much stronger than single flexure designs, this also allows cyclic testing at higher frequencies
  • Versions available for use in vacuum environments (consult factory)
  • May be left on through specimen failure
  • High purity alumina ceramic rods (1200 °C) or alpha grade silicon carbide rods (1600 °C) are available


The key specifications of the Model 3580 extensometers are as follows:

  • Excitation: 5 to 10 VDC recommended, 12 VDC or VAC maximum
  • Output: 2 to 4 mV/V nominal, depending on model
  • Temperature range: Standard is -40 °C to +1000 °C (-40 °F to 1832 °F)
  • Linearity: ≤0.15% of full scale measuring range, depending on model
  • Specimen size: Works with sample diameters from 4.5 to 16 mm (0.18” to 0.63”)
  • Cable: Integral, ultra-flexible cable, 2.5 m (8 ft) standard
  • Contact force: Adjustable, 100 to 300 g typical


The following are the options available with the Model 3580 extensometers:

  • Special rods are available for large specimens
  • Shunt calibration
  • Ceramic rods for testing to 1200 °C or 1600 °C
  • Model 2050 constant temperature water re-circulating bath
  • Connectors to interface to almost any brand test equipment

3580 High Temperature Diametral Extensometers for Strain Measurements at Temperatures to 1000°C


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