A Cross-Scanner of the type
K-50 is used for measurement of Possion's ratio
at a climatic chamber up to 250 °C. The scanning range at the sample
is 50 mm for longitudinal and lateral strain. The system is
integrated in the tensile tester and adjusted
for use at the climatic chamber.
The climatic chamber was modified by Fiedler Optoelektronik GmbH. An evacuated tube (type "steel") is used to guide the laser beams close to the specimen in order to minimize the effects of air flow to the accuracy of the measurement.
The mounting of the laser extensometer provides vertical adjustments and easy motion of the laser extensometer into and out of the climatic chamber. Although the extensometer is heavily integrated into the testing equipment, the K-50 as well as the chamber can easily be moved away.