23. A recording aneroid sensor (microbarograph) located in the labora- 

 tory building was also used to continuously record atmospheric pressure varia- 

 tion. The microbarograph was manufactured by Weathertronics Incorporated, 

 Sacramento, Calif. 



24. The microbarograph was compared daily with the NWS's aneroid barom- 

 eter, and adjustments were made as necessary. Maintenance of the microbaro- 

 graph consisted of inking the pen, changing the chart paper, and winding the 

 clock every 7 days. During the summer, a meteorologist from the NWS (Norfolk, 

 Va.) checked and verified the operation of the barometer. 



Rain gage 



25. A 30-cm weighing rain gage manufactured by the Belfort Instrument 

 Company, Baltimore, Md., measured daily precipitation. It was located near 

 the instrument shelter 46 m behind the dune. The manufacturer's specifica- 

 tions indicated that the instrument accuracy was 0.5 percent for precipitation 

 amounts less than 15 cm and 1.0 percent for amounts greater than 15 cm. 



26. A 15-cm-capacity "true check" clear plastic rain gage with a 

 0.025-cm resolution, manufactured by the Edwards Manufacturing Company, 

 Alberta Lea, Minn., was used to monitor the performance of the weighing rain 

 gage. This gage, located near the weighing gage, was checked daily; very few 

 discrepancies were identified throughout the year. 



Wind speed and direction 



27. Winds were measured from the top of the laboratory building at an 

 elevation of 19.1 m (Figure 2) by using a Sky^ane Model W102P anemometer manu- 

 factured by the Weather Measure Corporation, Sacramento, Calif. Wind speed 

 and direction data were incorporated into the automated data collection and 

 analysis program and were also collected continuously on a strip-chart 

 recorder. The Weather Measure Corporation specifies an accuracy of 



±0.45 m/sec below 13 m/sec and 3 percent at speeds above 13 m/sec, with a 

 threshold of 0.9 m/sec. Wind direction accuracy is ±2 deg with a resolution 

 of less than 1 deg. The anemometer was calibrated semiannually at the 

 National Bureau of Standards in Gaithersburg, Md., and was within the manu- 

 facturer's specifications. 



19 



