DBX large deformation extensimeter is generally used to measure the elongation of samples with deformation of more than 50%. The measuring range is 0 ~ 600mm(standard type) and 0 ~ 900mm(high type). Generally, the support can be rotated, lifting installation mode, through rotation, can provide greater test space; By lifting, the two Spaces of the testing machine can use the large deformation extender, and the measuring range of the large deformation extender can be effectively used.