3548COD High Temperature Furnace COD Gages (1200 °C or 1600 °C) for Fracture Mechanics Testing

The 3548COD models are high temperature COD gages designed for use in split type materials testing furnaces with a slot for the ceramic rods. These extensometers are furnace bracket mounted and water-cooled, and can be used at 1200 °C (2200 °F). This high-temperature option allows the units to be used at 1600 °C (2900 °F). The Model 3548COD extensometers are specifically designed for fracture mechanics testing.

  • 36 extensometer models are available in thousands of variations. Epsilon’s focus on helping customers has resulted in the development of models that cover almost any test method.
  • Operation of these extensometers, and all other Epsilon’s extensometers, is verified to applicable standards such as ISO 9513 or ASTM E83 using in-house calibration systems, which are calibrated with Epsilon’s laser interferometer system
  • Providing more than 20 years of service to the materials testing community, Epsilon stands behind its products to meet the critical application requirements of users

The COD gages are mounted on a water-cooled bracket, which is mounted on the furnace side cut-out, or with optional load frame support brackets. Additionally, high purity alumina rods are supplied with the standard temperature version (to 1200 °C). The high temperature option is furnished with alpha grade silicon carbide rods.

Rods are made to order to the length needed for the customers’ furnace. Mounting brackets can be incorporated with the furnace cut-out. Optional load frame mounting brackets are also available from Epsilon to fit the customers’ test frame. For best performance with this model, contact edges on the test sample should be somewhat rounded (not sharp knife edges).

The Model 3548COD extensometers are strain gaged devices, so they can be used with any electronics designed for strain gaged transducers. They are often connected to a test machine controller. The signal conditioning electronics for the extensometers is generally included with the test machine controller, or may often be added.

In this case, the extensometer is delivered with the appropriate connector and wiring to plug directly into the electronics. For systems that lack the required electronics, Epsilon offers a range of solutions, enabling the extensometer output to be connected to chart recorders, data acquisition boards, or other equipment.


The key features of the Model 3548COD extensometers are as follows:

  • Full bridge, 350 ohm strain gaged design for compatibility with almost any test system
  • Rugged, dual flexure design for strength and improved performance
  • May be left on through specimen failure
  • All units come with either alpha grade silicon carbide rods (1600 °C) or high purity alumina ceramic rods (1200 °C)
  • Includes a high-quality, foam-lined case and a spare set of ceramic rods
  • All standard units meet current ASTM E1820 requirements for accuracy. A test certificate is also included.


The following are the specifications of Model 3548COD extensometers:

  • Excitation: 5 to 10 VDC recommended, 12 VDC or VAC max.
  • Linearity: ≤0.15% of full scale measuring range, based on model
  • Output: 2 to 4 mV/V, nominal, based on model
  • Temperature Range: Standard (-ST) is to 1200 °C (2200 °F), optional (-HT) 1600 °C (2900 °F)
  • Operating Force: 30 g typical
  • Cable: Integral, ultra-flexible cable, 2.5 m (8 ft) standard


The following optional accessories are provided for the Model 3548COD extensometers:

  • Shunt Calibration
  • High-temperature option (-HT suffix) for use to 1600 °C
  • Load frame mounting brackets
  • Connectors to interface to almost any brand test equipment

3548COD High Temperature Furnace COD Gages (1200°C or 1600°C) for Fracture Mechanics Testing


Other Equipment by this Supplier

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.