Lap electrical sensing surface of the sensor commonly used in the specific power of 0.8 ~ 2.3kW / cm2 quenching case , when the quench zone is wide, the area of the large, multi-turn must be considered electrically simultaneous hardening induction coil or a continuous hardening . High frequency hardening is generally continuous with a single turn electrical induction coil, heating efficiency due to the high-frequency hardened thin, and lap electrical sensing conductor area is easy to control the quenching starting end position, the process to reduce the size of flexible tape. For frequency quenching, since the heating efficiency is low, deeper heat penetration depth, when the machine bed continuous quenching workpieces of large-scale, multi-ring to electrically sense conductors quenching, usually double circle, the electric somatosensory bezel warm, after laps Heat and quench by self-spraying. 

Machine tool guide rail quenching equipment : http://www.songdaokeji.com/plus/view.php?aid=208