Extensometers

Model 100S Long Travel Extensometer

The Tinius Olsen model 100 S is designed as a dual purpose extensometer to measure E modulus and offset yield stress (proof stress) on relatively high modulus materials while also providing the ability of measuring high elongations up to break.

A typical application is the testing of polycarbonate, where a high resolution system is required to measure the E modulus (Youngs modulus) and a secondary system is required to measure elongation to the point of break, which, typically, could be as high as 200% strain. Other materials for which the 100 S extensometer is ideally suited include polyurethane, polyethylene (PET), glass reinforced plastics (GRP) and aluminum alloys. 

The unique design ensures an extremely low tracking force for testing sensitive materials and a construction which is sufficiently robust to withstand the release force when the specimen breaks. An important feature is the ease with which the extensometer clamps can be attached to the specimen, resulting in very rapid testing throughput.

Extension is measured by attaching two counterbalanced extensometer clamps to the specimen at a pre-selected gauge length. When tensile forces are applied to the specimen by the testing machine, the slightest change in gauge length is measured by a precise LVDT transducer. If the range of this LVDT transducer is exceeded, measurement of elongation and strain transfers to an optical encoder. Signals from the LVDT and optical encoder are fed into the signal conditioner interface for processing.

The 100 S extensometer can be fitted to all twin screw materials testing machines and must be used under software control.