The BOD5 content is an important indicator of water quality; we took the BOD5 from Lun River of Xiaogan as the object of......

通过误差分析与计算，论证了０．０１ｍｍ／ｍ合象水平仪不能满足公差为７μｍ的机床工作台平面度检定精度要求，采用０．００５ｍｍ／ｍ自准直仪或电子水平仪可获得满意的检定......