求翻译：每米允许1毫米以内的误差，中空部分49.5*20 毫米，壁厚1.2毫米，中间胶合2个水银管，静电塑料喷漆，两端各用1个浅蓝色塑料套保护，在一边印上浅蓝色的公制刻度。是什么意思？

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Permitted per meter within 1 mm of error, the hollow portion of the wall thickness mm 49.5*20 1.2 mm, middle gluing 2 water silver tube, yellow static plastic spray paint to each end of the 1 light blue plastic sleeve protection, printed on one side in the light blue for metric scale.

Each rice permits 1 millimeter within the error, the spatial part 49.5*20 millimeter, the wall thickness 1.2 millimeters, the middle agglutination 2 mercury tubes, the decadent static electricity plastic sprays paint, the both sides protect respectively with 1 light blue plastic wrap, in one side In

Allow error of less than 1 mm per meter, hollow section 49.5*20 mm, thickness 1.2 mm, glued 2 mercury tube in the Middle, and yellow static plastic spraying, with 1 light blue plastic sleeve on each end to protect, on one side and metric scales printed on light blue.

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