天气预报 > 其他 > 电线怎么区分几平方的
电线怎么区分几平方的
更新时间: 2020-11-12 00:00:00  

电线的平方数,指的是电线导体的截面积。有经验的人目测可以看出来。单股线判断方法:1、剥去绝缘层,用游标卡尺测量测量金属线直径(用D表示)。2、计算金属线横截面,公式为:S=3.14*(D/2)*(D/2),即圆的面积公式。

关键词: 电线 怎么 区分 平方

电线怎么区分几平方的相关经验

天气预报

最新推荐

页面:/news/view-452732/ | 耗时:0.9290 s | 内存:2.11 MB | 查询:4 | 缓存读取:3 写入:0 | 加载文件:25
select * from tbl_Articles WHERE ArticleID=452732 LIMIT 0,1
select * from tbl_Articles_data WHERE ArticleID=452732 LIMIT 0,1
select * from tbl_Articles_sphinx where id=452732 LIMIT 0,1
SELECT ArticleID,Title FROM tbl_Articles WHERE ArticleID IN(1051419,1069223,1074712,1064847,1071271,1085390,1074880,1034501,1051075,1058075,1061912,1075901,1057595,1056160,1080432,1078565,1079051,1128783,1076193,1087133,1078903,1054934,1065795,1041639,1041627,1064945,1072200,1049510,1080404,1064667) ORDER BY field (ArticleID,1051419,1069223,1074712,1064847,1071271,1085390,1074880,1034501,1051075,1058075,1061912,1075901,1057595,1056160,1080432,1078565,1079051,1128783,1076193,1087133,1078903,1054934,1065795,1041639,1041627,1064945,1072200,1049510,1080404,1064667)