A.132°24′36″ B.227°35′24″ C.21°21′12″ D.228°24′36″
A.-06″ B.+06″ C.-12″ D.+12″
A.水準(zhǔn)管軸垂直于豎軸,即LL⊥VV B.視準(zhǔn)軸垂直于橫軸,即C C⊥HHC.橫軸垂直于豎軸,即HH⊥VV D.視準(zhǔn)軸垂直于圓水準(zhǔn)器軸,即CC⊥L′L′