To correct for mechanical imperfections (collimation errors), always take two observations.
Remove the instrument from its case (hold it by the handle or standards, never the telescope). Screw it onto the tripod base. Do not over-tighten. hilger watts theodolite manual
While the basic principles of surveying remain the same, the contains specific "constants" and lubrication charts unique to these British instruments. For example, the specific way the internal illumination system (using mirrors or battery lamps) interacts with the glass circles is unique to the Watts design. 6. Where to Find Manuals Today hilger watts theodolite manual
: Vibrations that can knock a high-precision reading off by several seconds of an arc. hilger watts theodolite manual