daily extreme temperatures. The thermometers were housed in an NWS instrument 

 shelter located 91 m behind the dune (Figure 2). The shelter was designed 

 with louvered sides, a double roof, and a slatted bottom for housing instru- 

 ments requiring protection from direct sun. 



47. The actual temperature readings at the time the thermometers were 

 read (i.e., the present temperature) were compared to ensure accuracy of maxi- 

 mum and minimum values. Maintenance consisted of periodic removal and clean- 

 ing of the thermometers with soap and clean water and lubricating the support 

 used to hold and reset the instruments. 



Rain gage 



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

 Company, Baltimore, Maryland, used to measure the daily amount of precipita- 

 tion, was located near the instrument shelter 87 m behind the dune (Figure 2). 

 The manufacturer's specifications indicated that the instrument accuracy was 

 ±0.5 percent for precipitation amounts less than 15 cm and ±1.0 percent for 

 amounts above 15 cm. 



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

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

 Lea, Minnesota, was used to monitor the performance of the weighing rain gage. 

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

 discrepancies were identified throughout the year. The weighing rain gage re- 

 quired little maintenance except to wind the clock and ink the pen. The pen 

 mark on the chart records did "bleed" or drip down when a driving rain was 

 directed at the access door. 



Sling psychrometer 



50. A sling psychrometer was used to measure wet and dry bulb tempera- 

 tures for determining relative humidity and dew point. The psychrometer had 

 two thermometers mounted in a frame which was rotated rapidly. A moistened 

 muslin wick was attached to the bulb (i.e. wet bulb) of one of the thermom- 

 eters, and the device was whirled to ventilate both thermometers. The wet and 

 dry bulb temperatures were read, and a set of NWS tables were used to deter- 

 mine the dew point. 



51. These thermometers required little maintenance except to change the 

 muslin wick every month or two and to clean the sling and thermometers with 

 soap and water. The instruments were not calibrated, but the thermometers 

 were compared daily to detect any bias or malfunction. 



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