Single yarn breaking strength and single strength coefficient of variation are one of the main indicators for measuring yarn quality in the world, and they are also the most important routine inspection items.  According to IS02062-1972 "Test Method for Breaking Strength and Elongation at Breaking of a Single Yarn" and the domestic equivalent standard GB3916-89, under the standard atmospheric test conditions, a single yarn specimen is stretched with a strength tester until it breaks, and the elongation at break is indicated.  The single yarn strength meters available are:

• Constant velocity traction strength tester (CRT)

• Constant velocity Load Strength Tester (CRL)

• Constant velocity Elongation Load Strength Tester (CRE)

Internationally, it is now widely used to design electronic strength meters according to the CRE drafting principle.For example, the Swiss Uster automatic single yarn strength meter has a variety of automatic functions, such as TENSOMATI type, TENSORAPID type, in addition to NSTRON company-1151 automatic continuous yarn strength meter, TEXTECHWO company STATIMAT II, M type yarn automatic tensile rhythm tester, etc., are the international advanced single yarn strength test equipment, China's more advanced automatic single yarn strength meter in recent years YG022, YG023 type and so on.

Test calculation formula:

• Average breaking strength (CN) = sum of breaking strength (CN) / number of experiments

• Average Strength at Break (CN/ex) = Average Strength at Break (CN) / Average Linear Density (tex)