After the invention of the "lightening plumment",another kind of new plummet--laser plummet has been born and got Chinese patent(No.ZL0000.). It makes project measures in mining?
After the invention of the "lightening plumment",another kind of new plummet--laser plummet has been born and got Chinese patent(No.ZL0000.). It makes project measures in mining?
文中报导了激光垂球 ,中国专利 (专利号 :ZL 0 0 0 0 . )。