a brief study on measurement systems in large scale metrology

1. LARGE SCALE METROLOGY
 USED IN PRODUCTION TECHNOLOGY GEOMETRIC
INSPECTION.
 LINEAR DIMENSIONS VARY FROM 1 METRE TO 100 METRE.
ATTRIBUTES
 SENSOR READING RELATED TO MEASURAND.
 CHALLENGING TOLERANCES INSPITE OF LARGE DIMENSIONS.
 INFLUENCE OF GRAVITY ON OBJECT MEASURAND.
 NEED FOR RIGHT TIME PRODUCTION I SMALL BATCHES.
 CLASICAL QUALITY ASSURANCE TOOLS ARE DIFFICULT TO DAPT.

2. MEASUREMENT SYSTEMS IN LARGE SCALE
METROLOGY

3. EXAMPLES OF LARGE SCALE
METROLOGY
 PRODUCTION OF GAS AND
STEAM TURBINES.
 FUSELAGE OF AN AIRPLANE
BODY.
 WIND MILLS.
 SHIP CONSTRUCTION
LASER TRACKER
 Laser trackers are instruments
that accurately measure large
objects by determining the
positions of optical targets held
against those objects.
 The accuracy of laser trackers is
of the order of 0.025 mm over a
distance of several metres.
 Some examples of laser tracker
applications are to align aircraft
wings during assembly and to
align large machine tools