Interferometric and mechanical measurements of gauge blocks

Description

Consultation will be performed during the visit in Length Laboratory of BEV.

The following topics will be discussed:

• methods of interferometric and mechanical measurements of gauge blocks
• measuring instruments for gauge blocks
• uncertainty evaluation

Final Report 2001-06-15

Consultations were performed during the visit of two representatives of GUM in BEV.
Following topics were discussed:

• gauge blocks calibration (0,5 to 100 mm) by optical interferometry with Κöstersinterferometer computer analysis and capturing of the data of fringe pattern image,measurements of temperature, pressure and humidity in the interferometer, temperature of the gauge block stabilisation, optical method of focal length measurement, the effects of collimation and oblique incidence in interferometer, conveying the light of Cd lamp and He-Ne laser to the interferometer using optic fibre, software validation
• gauge blocks calibration (0,5 to 100 mm) by mechanical comparison for gauge blocks of similar and dissimilar materials - correction values due to elastic deformation and uncertainty evaluation (particularly uncertainties in measuring temperature)
• quality system in BEV – labelling of measuring equipment, numbering of calibration procedures, environmental conditions records, storage and handling, personnel
   

Measuring instruments for length as iodine stabilized lasers, 30 m bench for tapes calibration, 3002 CMM measuring machine were also presented and discussed.