....Model 3800 High Elongation
    Extensometer ....

Designed for plastics, rubber and elastomer testing, these extensometers have very long travels. Unique design allows testing to failure and minimizes interaction with the sample.

The main body of this unique extensometer remains stationary during testing, held in position by the adjustable magnetic base included. Only the very light, small traveling heads move as the sample elongates during a test. These attach to the sample with small spring clips. Each head pulls a cord out from the extensometer as the head moves.

This extensometer uses high precision, low friction potentiometers to measure the travel. They are hybrid wire wound and conductive plastic, to provide infinite resolution and excellent long term stability. The extensometer is driven by an excitation voltage and has output proportional to the input. This is like strain gaged units, except in the model 3800 the output is much higher, typically 2 to 5 VDC.

The output from the electronics is readily interfaced with most existing test controllers, and may be directly input to data acquisition systems and chart recorders. For test controllers, the high level output means the gain (amplification) of the control electronics is set much lower than with strain gaged extensometers. This model is also available with low output to match strain gaged extensometers. This simplifies interfacing with existing signal conditioners designed for strain gaged transducers.


High travels, to 500 mm (20 inches).
Available in 25 and 50 mm gage lengths (also 1 and 2 inches).
Low influence on test samples. Only 10-20 grams operating force.
Main body is stationary. Only lightweight traveling heads move. Not damaged by specimen failure.
Low cost, high accuracy elastomer strain measurement.


Linearity: 0.15%
Output: 2 to 5 VDC, depending on model (at 10 VDC input)
Input: 10 VDC typical, 15 VDC or VAC max. Travel: tension only.
Operating force: 10-20 grams typical, each head.


2 mV/V output for use with electronics designed for strain gaged sensors.

Model 3800 Available Versions:
ANY combination of travel and gage length listed below is available.

Gage Length
25 mm 1.000 in.
50 mm 2.000 in.

125 mm or 5 inches
250 mm or 10 in.
500 mm or 20 in.

example: 250 mm travel in a 25 mm gage length version
results in total measuring range of 1000 percent strain.

For more information on calibration services or digital retrofits please contact us.



300 Buttertown Road
Emlenton, PA 16373
(724) 867-6664 or (800) 793-1870
FAX (724) 867-1346

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