Abstract

Accurate humidity and wind measurements are critical when characterizing the atmosphere at a high-energy laser test facility. The 1990 General Eastern Hygrometer (1200 Series) calibration curve produced by the National Institute of Standards and Technology displayed resistance as a nonunique function of dewpoint temperature. In 1991, a revised standard calibration procedure was developed. This new procedure corrected this problem and changed the formerly 5-7°C dewpoint differential between humidity sensors to a 1°C separation. A wind tunnel calibration of seven polypropylene and six polystyrene R.M. Young Gill anemometers (Model 27106) demonstrated that the polypropylene anemometers have a 0.4 m/s separation between averaged starting and stopping thresholds; the polystyrene thresholds were less than polypropylene thresholds and well below critical cross-wind laser beam ventilation. All 13 anemometer calibration curves were unique. Combining the 13 calibration curves into one generic operational curve created an uncertainty ≤8%. Collating curves by sensor type produced uncertainties of ≤3.4% for polypropylene anemometers and ≤7.0% for polystyrene anemometers.

© 1992 Optical Society of America