IMPROVEMENTS TO NIST'S AIR SPEED CALIBRATION SERVICE

Abstract

We discuss five significant improvements to the Air Speed Calibration Service conducted by the National Institute of Standards and Technology (NIST): 1. Reduced-uncertainty calibrations of the secondary standard [Laser Doppler Anemometer, (LDA)] using a spinning disk, 2. Reduced-uncertainty LDA measurements that account for the position-dependence of the air speed in the test volume and for window effects on the LDA, 3. Improved repeatability, precision, and ease of calibrations by using automated data acquisition and PID air speed control, 4. Optical Character Recognition data acquisition system for anemometers lacking electrical outputs 5. Up-to-date uncertainty budget Also, we present the results (with uncertainties) of Pitot tube calibrations.