Working Principle

The measuring system consists of two measuring heads with a sender and receiver.

Sender and receiver are mounted on a base plate. The sender illuminates two areas at the specimen with a laser line. Within each laser line a marker is placed.

The position of the markers inside the laser line is observed by the receiver. A position sensitive detector generates a signal for the measuring computer.

The computer records the position signals of both markers and the load signal with correct phase information. Based on measuring length and position information the strain is calculated.