DEW-POINT TEMPERATURE ERROR FROM MEASURING DRY-BULB TEMPERATURE AND RELATIVE-HUMIDITY

A component error analysis was performed to relate the accuracy of mea sured values of dry bulb temperature and relative humidity to errors i n calculated dew point temperature. Dew point temperature errors were found to be greatest for dryer air (less than about 50% relative humid ity) and to increase proportionately with dry bulb temperature. Error calculations for various combinations of dry bulb temperature, relativ e humidty, and measurement errors in each variable which are represent ative of current commercial sensors, are provided in tabular format. T he magnitude of dew point errors from these calculations suggests that modern applications such as automated weather stations can have signi ficant errors in computed dew point temperature, and even for very acc urate sensors the dew point error can exceed twice the magnitude of th e dry bulb sensor error for dryer conditions.