To measure the part of a process of a yarn breakage by detecting the occurrence of a yarn breakage in a designated section of a running yarn, detecting passing of the end of a broken yarn in a reference position downstream from the designated section, and measuring the yarn breakage occurrence position from the reference position.
A tension detector 11 for measuring yarn tension of a yarn processing area is provided between a frictional false twister 6 and a delivery roller 7, and a yarn detector 12 for detecting passing of the end of a broken yarn in a reference position is provided in a designated position which is a reference position between guide rollers 2 immediately before winding. A tension signal form the tension detector 11 is largely lowered simultaneously with the occurrence of a yarn breakage, and a time yarn breakage occurrence signal is generated according to the level change. When a passing signal is output as a stepwise signal from the yarn detector 12 when the end of a broken yarn passes a reference position. The amount of time elapsed from the time when a yarn breakage occurrence signal is generated to the time when a passing signal is generated is measured to measure the yarn breakage position from the reference position.
HAMASU BUNJI
SASAKI MITSUMASA
