3.7 Deformation diagram (hysteresis) of the seat squabA test machine according to DIN 51220 class 1 shall be used.The test is performed on a rigid, positively engaging backing.The hysteresis characteristic values are recorded in the compression test according toDIN 53579-1; representation see Appendix A.1A zero-point setting (displacement and load) is to be made after achieving the respectivepreliminary force.