spread-tail wind vane located on the top of the laboratory building at an 
elevation of 19.1 m (Figure 2). The accuracy of the speed transmitter and in- 
dicator assemblies was 1 percent up to 100 m/sec and 2 percent over 100 m/sec. 
The wind direction transmitter and indicator assemblies were accurate to 
+5 deg at an air speed of 0.26 m/sec or greater. 
25. The wind speed and direction were recorded on a battery-powered 
Esterline-Angus recorder. Problems with the recorder's clock, tape advance 
mechanism, and pen actuator (for indicating direction) were found, and the 
unit required frequent maintenance. 
26. On 30 March, the system was replaced with a Skyvane Model W102P 
anemometer manufactured by the Weather Measure Corporation, Sacramento, 
Calif. Wind speed and direction were recorded continuously on an MFE Corpora- 
tion, Salem, N. H., two-channel chart recorder and were incorporated into the 
automated data collection and analysis program using the computer. The ane- 
mometer, calibrated at the National Bureau of Standards in Gaithersburg, Md., 
showed an accuracy of +1 percent below 11 m/sec and +3 percent above 11 m/sec. 
Microbarograph 
27. A recording aneroid sensor (microbarograph), used to measure atmo- 
spheric pressure, responded to pressure changes on the order of 0.169 mb. 
Microbarographs manufactured by the Belfort Instrument Company, Baltimore, Md. 
(used before 9 April 1982), and Weathertronics Incorporated, Sacramento, 
Calif., were located inside the laboratory building, 9 m above NGVD. 
28. The microbarograph was compared daily to an NWS aneroid barometer, 
and adjustments were made as necessary. Maintenance of the microbarographs 
consisted of inking the pens, changing the chart paper, and winding the clocks 
every 3 or 7 days for the instruments used before 30 March or after, 
respectively. 
29. An electronic atmospheric pressure sensor with analog output, manu- 
factured by Yellow Springs Instruments Company, Inc. (YSI, Inc.), Yellow 
Springs, Ohio, was installed in the building in late February and included in 
the automated data collection program. Data from this gage were compared with 
the microbarograph once a week to ensure proper operation of the instruments. 
Air temperature 
thermometers--maximum/minimum 
30. NWS maximum and minimum thermometers were used to determine the 
daily extreme air temperatures. The thermometers were housed in an NWS 
18 
