Beam or Slab height determine by Auto Level Machine by method of inverted staff Reading , Surveying

Beam or Slab height determine by Auto Level Machine by method of inverted staff Reading , Surveying Land Surveying . How to find the wall height by auto level machine ? how to find the slab height by auto level machine ? How to find the Beam Height from Floor by Levelling Machine ? Land Surveying . How To Find the Excavation Level by Auto Level Machine ? Land Surveying . Basement or lay pipe line