The laser extensometer - type cross-scanner is used for simultaneous contact free measurement of longitudinal and lateral strain of specimens at uniaxial load. This scanner type is optimised for determining Possion's ratio..

Before starting the experiment, two marks for longitutinal strain and two marks for lateral strain are put on the sample. One laser beam for each measuring direction is directed onto rotating optical flats. During entering and leaving the laser beam is refracted at two opposite planes of the optical flat which results in an identical refractive angle. By the rotation of the optical flat, the laser beam is deflected in parallel to itself and is directed onto the specimen. The laser extensometer scans the measuring range with a visible laser beam. After automatically determining the reference length at the beginning, the positions of the marks are continuously observed throughout the experiment.

Technical Data	K-50	K-100	K-130
Working Distance	100-300 mm	100-300 mm	100-300 mm
Longitudinal Strain
Scan Range on Specimen	50 mm	100 mm	130 mm
Resolution (micron)	0.1 um	0.25 um	0.3 um
Accuracy (DIN EN 10002-4)	Class 0.2; 0.5; 1	Class 0.5; 1	Class 0.5; 1
Scanning Rate	50; 100 Hz	50; 100 Hz	50; 100 Hz
Duration of each Scan at Specimen	5.0 ms	5.0 ms	5.0 ms
Scanning Speed at Specimen	10 m/s	20 m/s	27 m/s
Lateral Strain
Scan Range on Specimen	50 mm	50 mm	50 mm
Resolution (micron)	0.1 um	0.1 um	0.1 um
Accuracy (DIN EN 10002-4)	Class 0.5	Class 0.5	Class 0.5
Scanning Rate	50; 100 Hz	50; 100 Hz	50; 100 Hz
Duration of each Scan at Specimen	5.0 ms	5.0 ms	5.0 ms
Scanning Speed at Specimen	10 m/s	10 m/s	10 m/s
Specimen Surface	plane or structured (Components)	plane or structured (Components)	plane or structured (Components)