Hualong WSC Series is used to determine stress-relaxation of metal, such as pre-stressed concrete strand, pre-stressed concrete bar, steel rope and so on., the specimen is deformed a given amount and decrease in stress is recorded over prolonged period of exposure at constant elevated temperature. Application: EN10391:2003 stress relaxation test method of metal and ASTM E328- 02(2008) Standard Test Methods for Stress Relaxation Tests for Materials and Structures.