High Temperature Diametral Extensometers (1000 °C) – Model 3580

Model : 3580

Applied Standard

  • This model is for diametral strain measurement with furnace and induction heating systems. 
  • Quartz rods and water-cooling allow the unit to be used for high temperature testing of metals, ceramics and composites. With induction heating, this model often can be used without water-cooling. 
  • When used in furnaces, the extensometer is often mounted directly to the furnace side cut-out. Optional load frame mounting brackets are available for supporting the extensometer in cases where furnace mounting is not possible. These optional mounts are used with induction heating or furnace systems. 
  • The Model 3580 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.


  • May be left on through specimen failure.
  • 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. 
  • Suitable for measuring Poisson’s ratio per ASTM E132 with most materials and specimens.
  • Each unit comes with a spare set of quartz rods, universal water-cooled mounting bracket and a foam lined storage case.
  • 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). 
  • High purity alumina ceramic rods (1200℃) or alpha grade silicon carbide rods (1600℃) are available.

Load frame


  • Special rods are available for large specimens 
  • Ceramic rods for testing to 1200℃ or 1600℃
  • Model 2050 constant temperature water re-circulating bath 
  • 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: ≤0.15% of full scale measuring range, depending on model
  • Temperature Range: Standard is -40℃ to +1000℃ (-40°F to 1832°F)
  • Cable: Integral, ultra-flexible cable, 2.5 m (8 ft) standard
  • Specimen Size: Works with sample diameters from 4.5 to 16 mm (0.18 to 0.63 inch)
  • Contact Force: Adjustable, 100 to 300 g typical