Abstract
A LDV calibrator used as the national standard of air speed was improved and the measurement uncertainty was estimated quantitatively in detail. A LDV is suitable for a transfer standard of air speed derived from lergth and time, but there are few examples of uncertainty analysis required for establishment of traceability. Thus, former LDV calibrator was developed to generate various velocities with a fine wire simulating a particle suspended in fluid flow. In this report, improvements were performed on the calibrator mechanisms, system configurations, measurement procedures and evaluation method. With these efforts, the best measurement capability (BMC) of calibration from 0.063% to 0.50% was achieved at the wire speed from 1.3 m/s to 40 m/s for backscatter LDV without reflector optics. The LDV under test showed remarkable velocity dependency at every filter range in the actual calibration result.
