8 research outputs found
Determination Model of Phase-Change Correction for High Precision Gauge Block Calibration
AbstractWhen gauge blocks are calibrated by the laser interferometer technique, phase-change corrections play a crucial role in the measurement uncertainties. In order to reduce the source of uncertainty, phase-change correction must be known and be compensated to the measured results. We present here a determination based on knowledge gained from the stacking method and the known value of phase correction of quartz. It is a fast and robust method. Phase-change correction of any pair of auxiliary plates and gauge blocks can be calculated by using our model. This method is suitable for the national metrological institutes (NMIs), calibration laboratories and industries where calibration of various gauge block materials are carried out and measurement uncertainty within 30 nm is adequate. The experimentally observed phase-change corrections were compared with the calculated values according to our model. The comparison illustrates a good agreement. The measurement uncertainty of gauge block calibration using our interferometer system is 24 nm
Development of the Probe Calibration System for the Roundness Measuring Machine
AbstractThe calibration system of the probing system used in roundness measuring instrument has been developed at the national institute of metrology (Thailand), NIMT. The calibration system was designed, constructed, validated and used to calibrate sensitivity and linearity of the probing system. This calibration system can help to reduce use of magnification setting standards which are need to be calibrated by the oversea national metrology institutes (NMIs) in order to retain traceability chain to the SI unit. The calibration system does not only help in reducing expense due to purchasing, maintenance and calibration of the magnification standard but also yield a measurement technology that can be transferred to the industries. The measurement uncertainty for the roundness measurement is [9.4, 0.01ÃR] nm where R is the measured roundness error of the workpiece in nm
Fundamental studies of inorganic and organic aqueous aerosols using optical tweezers
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
New Measurement Method and Uncertainty Estimation for Plate Dimensions and Surface Quality
Dimensional and surface quality for plate production control is facing difficult engineering challenges. One of these challenges is that plates in large-scale mass production contain geometric uneven surfaces. There is a traditional measurement method used to assess the tile plate dimensions and surface quality based on standard specifications: ISO-10545-2: 1995, EOS-3168-2: 2007, and TIS 2398-2: 2008. A proposed measurement method of the dimensions and surface quality for ceramic oblong large-scale tile plate has been developed compared to the traditional method. The strategy of new method is based on CMM straightness measurement strategy instead of the centre point in the traditional method. Expanded uncertainties budgets in the measurements of each method have been estimated in detail. The capability of accurate estimations of real actual results for centre of curvature (CC), centre of edge (CE), warpage (W), and edge crack defects parameters has been achieved according to standards. Moreover, the obtained results not only showed better accurate new method but also improved the quality of plate products significantly