604 



TABLE 638.— RELATIVE HUMIDITY FOR VARIOUS PRESSURES AND 

 DRY-BULB TEMPERATURES (concluded) 



TABLE 639.— RELATIVE HUMIDITY, WET AND DRY THERMOMETERS 



This table gives the relative humidity direct from the difference between the reading 

 of the dry (t°C) and the wet (ti°C) thermometer. It is computed for a barometer reading 

 of 1000 mb. The wet thermometers should be ventilated about 3 meters per second. Changes 

 due to different pressure can be calculated from the data given in Tables 634 and 640. 



Temperatures of dry thermometer, t° 



SMITHSONIAN PHYSICAL TABLES 



