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High-temperature extensometer

The spring force is less than 500 grammes Description
The spring-loaded axial high-temperature extensometer consists of an upper and lower arm which maintain contact with the specimen without the necessity for locating ridges or indents. This is achieved by means of a spring-block outside the furnace/heating arrangement. The spring force is less than 500 grammes. Extensometer arms are available with ceramic points or fork ends ( see insets in illustration left ).
  • Si-Plan extensometers of this design have been in continuous use for over 10 years.
  • High-temperature extensometer Application
    Ideal for strain control cyclic fatigue and creep fatigue applications, where long term stability is essential.

    Manufactured from a special nickel alloy with high corrosion resistance even at temperatures in excess of 950°C.

    Operating temperature
  • Standard range: up to 850°C
  • Extended range: up to 950°C

    Gauge length
  • Standard range: 6 - 10mm
  • With additional plate: 6 - 25mm
    The gauge-length is set by the passive arm plate held in place by means of a locking-screw.

    Standard working range
    The standard working range of the extensometer is 1.1mm.
  • The extensometer arms can reach up to 180mm into a thermal enclosure Arm length
    The extensometer arms can reach up to 180mm into a thermal enclosure.
    A high-temperature matching furnace is also available Mounting adaptors
    Adaptors to mount the spring block from fatigue machine columns can be manufactured to customer specification.

    Test machine frequency
    Frequencies in excess of 10 hertz can be measured and controlled because of the low mass of the extensometer arms.

    A high-temperature matching furnace is also available. Voltage converter unit
    The extensometer is supplied complete with an extensometer capacitance to voltage converter unit. The capacitance to voltage converter unit produces a voltage proportional to the gap between a set of extensometer plates. A probe with a target of 8mm diameter has an operating range of 1.1mm. This allows ± 0.5mm displacement from a 0.6mm origin. A link is fitted inside the unit to provide zero output at 0.1 or 0.6mm.

    Extensometer classification
    The Si-Plan Electronics Research Ltd extensometer can achieve classification 0.5 as defined in EN 10002-4 : 1994.
    Supply voltage range
    Supply current
    Output for 1mm displacement
    Output change with supply voltage
    Linearity error
    Temperature coefficient of output at 0.6mm
    Temperature coefficient of output at 1.1mm
    Output noise at 0.6mm
    Output noise at 1.1mm
    Capacitance range for 10 volt output
    Frequency response
    ± 12V to ± 16V
    +12mA -7mA
    10 volts
    40mV/V @ 1.1mm
    ± 0.12% FS
    4mV rms
    9mV rms
    0.4 - 4.5 pF
    30 hertz with phase shift < 0.5°

    Room-temperature extensometer

    Accuracy to BS EN 10002-4 Grade 1.0 Lightweight: 55 grammes
    Robust design with integral gauge-length setting pin Hardened carbon steel wedge form knife edges (replaceable)
    Photographs above show extensometer model 676110.
  • Accuracy to BS EN 10002-4 Grade 1.0.
  • Lightweight: 55 grammes.
  • Robust design with integral gauge-length setting pin.
  • Hardened carbon steel wedge form knife edges (replaceable) attached to test piece by O rings. Other knife forms and attachments available on request.
  • User-configurable knife edges give 3 precise gauge length options on each of the 4 models (dimensions over):
  • User-configurable knife edges give 3 precise gauge length options
  • 10 to 20mm. 100 - 50% strain range.
  • 20 to 30mm. 50 - 33% strain range.
  • 30 to 40mm. 33 - 25% strain range.
  • 40 to 50mm. 25 - 20% strain range.
  • Low operating force: 0.3 newtons.
  • Nominal sensitivity: 1.6 mV/V/mm
  • Temperature coefficient: Standard temperature coefficient trimmed for steel specimens, ie 12 microstrain/°C.
  • Maximum operating temperature 80°C.
  • Linearity 0.2% for 0 - 2% strain range. 0.5% for 2 - 5% strain range. 1.0% for 5 - 10% strain range.
  • Bridge voltage range 5 - 10 volts.
  • Supplied with 2 metre cable fitted with 4-pin DIN plug.
  • Description
    The Si-Plan Electronics Research Ltd extensometer employs spring steel dual beam strain gauged sensing elements to measure displacement for
    • static tensile testing
    • fatigue testing
    Supplied with gauge length setting piece.
    Special requirements
    Si-Plan Electronics Research Ltd has a history of building special rigs to customer requirements. The company is able to carry over this service to its standard product range, giving a flexibility to meet the needs of each customer - and in-house CAD systems and CNC machining mean a realistic delivery time will be achieved.
    4-pin DIN plug connections 4-pin DIN plug connections
    350 Omhe bridge
    Dimensions Dimensions
    Dimensions in millimetres
    Model number Gauge length Height Width Depth
    A1 A2 A3 B C D
    676123 10 15 20 25 16 78
    676122 20 25 30 35 16 78
    676110 30 35 40 45 16 78
    676121 40 45 50 55 16 78
    Specifications may be updated. Check when ordering.

    Updated 20 April 2005

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    Si-Plan Electronics Research Ltd, Avenue Farm Industrial Estate,
    Birmingham Road, Stratford-upon-Avon, CV37 0HR, UK
    Tel International: +44 1789 205849 | Tel UK: 01789 205849
    Fax International: +44 1789 415550 | Fax UK: 01789 415550

    Si-Plan ISO 9001:2000