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, 0.01×R] nm where R is the measured roundness error of the workpiece in nm