Problem OutlineTo determine the position, size and shape of the band housing, in situ, for a hydroelectric turbine. The housing was 5.3metres in diameter and had an obvious damaged area.
SolutionThe laser tracker was selected as the ideal instrument for the measurements. From 2 locations at the top of the draft tube the lower guide bearing, crown and band rings were measured. The observable section of a housing was measured in a matter of seconds at a point spacing of 20mm. The results of the band housing measurements are shown in the diagram.
Benefits· Easily identify that the damaged area was not localised but that a large section of the housing was out of round.
· Provide readings for the in-situ borer to centre on based on the lower guide centre bearing 2.5 metres above the band housing.
· Fast measurement of complete 3D shape.