求翻译：先用丙烯酸酯对栅区进行二次涂覆，再将二次涂覆后的FBG封装在毛细铜管内，FBG在毛细铜管内处于有余长无应力状态，二次涂覆为裸FBG提供了有效的保护。是什么意思？

The gate area, use acrylate secondary coating, the the fbg package and then the secondary coating in the capillary brass, fbg is more than long without stress state in the capillary brass, the second coating to the bare fbg provide effective protection.

First of the grid with acrylic polyurethane (PU) for 2 times, and then coated with 2 times after the coating FBG package in the capillary FBG copper tube, copper tube in the capillary is stress-free status for more than 2 times, and the coating to provide a bare FBG effective protection.

Uses the propylene diethylene glycol dinitrate to carry on two times first to the grid area the spreading, after then two spreading FBG seals in the capillarity copper pipe, FBG is at in the capillarity copper pipe has -odd long unstressing condition, two spreading have provided the effective protec

Acrylate coating on the grid for the second time, then after the second coating of FBG packaged in a copper capillary tube, FBG copper capillary tube is a long unstressed State, secondary coating provides effective protection for bare FBG.

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