Abstract
In this study,we aim to establish traceability at calibration and thus enable certified flow measurement within a calibrated measurement system.Here,a new calibration method is presented for laser velocimetry.We developed a simple,unique method to establish traceability of its uncertainty.Our new method only requires a rotating disk and a precision linear stage to provide positional information. With past calibration methods.the uncertainty of the orbit radius of a scattering object was dominant because of the difficulty in accessing the true center of the rotation.This difficulty is solved with our new methodas it provides a reliable estimate of the or bit radius and hence the velocity of the calibration object through a linear regression.The uncertainty budget is examined throughout the calibration procedure.The traceability chain is established once the traceabilities are obtained to the translation stage and the motor used for rotating the calibration disk.We tested this new method with three different calibration setups and investigated their performances.The tests show that uncertainty could be determined as low as 0.14%,which is lower than the limit of an ordinary laser velocimetry around 0.3 %.
