A.豎軸 B.圓水準器 C.水準管軸 D.水準器
水準儀有DS0.5、DS1、DS3等多種型號,其下標數(shù)字0.5、1、3等代表水準儀的精度,為水準測量每公里往返高差中數(shù)的中誤差值,單位為:()
A.km B.m C.cm D.mm
M點高程Hm=43.251m,測得后視讀數(shù)a=1.000m,前視讀數(shù)b=2.283m。則N點對M點的高差hMN和待求點N的高程HN分別為:()
A.1.283m,44.534m B.-3.283m,39.968m C.3.283m,46.534m D.-1.283m,41.968m