Ask A Scientist© Weather Archive

name         Gabriel
status       student
age          30s

Question -   For a psychrometer, does exist any limit for maximum velocity of air?
I know it is one for minimum limit, for reach the saturation, but I would
like to know if it is a superior one?

Gabriel,

Yes, there is an upper, as well as a lower limit for airflow for a 
psychrometer,
although this varies a little depending on the kind of sensor used (mercury
thermometer, thermistor, or Platinum Resistance Temperature Detector for
temperature, capacitive element or dewcell for humidity, etc.).  The lowest
airflow recommended is 2 liters per minute, the maximum is about 6 liters
per minute.  The low end is the most important; the upper end is to prevent
too fast a drying of wicked humidity sensors and to prevent sensors
installed in the field from sucking in precipitation.

David Cook
meteorologist
Argonne National Laboratory
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