Psychrometric formula: Difference between revisions
From Glossary of Meteorology
imported>Perlwikibot No edit summary |
imported>Perlwikibot No edit summary |
||
| Line 9: | Line 9: | ||
</div> | </div> | ||
<div class="definition"><div class="short_definition">(Also known as hygrometric formula.) The semi-empirical relation giving the [[vapor pressure]] in terms of the [[barometer]] and [[psychrometer]] readings.</div><br/> <div class="paragraph">For temperatures in degrees Celsius, this formula is <div class="display-formula"><blockquote>[[File:ams2001glos-Pe60.gif|link=|center|ams2001glos-Pe60]]</blockquote></div> where ''T'' and ''T''<sub>''w''</sub> are the [[dry-bulb]] and [[wet-bulb temperatures]], respectively; ''e'' is the vapor pressure; ''e''<sub>''s''</sub>(''T''<sub>''w''</sub>) is the [[saturation vapor pressure]] at the wet-bulb temperature; and ''p'' is [[pressure]]. For temperatures below [[freezing]], with the wet bulb covered with [[ice]], 6.60 × 10<sup>-4</sup> is replaced by, approximately, 5.82 X 10<sup>-4</sup>.</div><br/> </div> | <div class="definition"><div class="short_definition">(Also known as hygrometric formula.) The semi-empirical relation giving the [[vapor pressure]] in terms of the [[barometer]] and [[psychrometer]] readings.</div><br/> <div class="paragraph">For temperatures in degrees Celsius, this formula is <div class="display-formula"><blockquote>[[File:ams2001glos-Pe60.gif|link=|center|ams2001glos-Pe60]]</blockquote></div> where ''T'' and ''T''<sub>''w''</sub> are the [[dry-bulb temperature|dry-bulb]] and [[wet-bulb temperatures]], respectively; ''e'' is the vapor pressure; ''e''<sub>''s''</sub>(''T''<sub>''w''</sub>) is the [[saturation vapor pressure]] at the wet-bulb temperature; and ''p'' is [[pressure]]. For temperatures below [[freezing]], with the wet bulb covered with [[ice]], 6.60 × 10<sup>-4</sup> is replaced by, approximately, 5.82 X 10<sup>-4</sup>.</div><br/> </div> | ||
</div> | </div> | ||
Latest revision as of 16:41, 25 April 2012
psychrometric formula
(Also known as hygrometric formula.) The semi-empirical relation giving the vapor pressure in terms of the barometer and psychrometer readings.
For temperatures in degrees Celsius, this formula is where T and Tw are the dry-bulb and wet-bulb temperatures, respectively; e is the vapor pressure; es(Tw) is the saturation vapor pressure at the wet-bulb temperature; and p is pressure. For temperatures below freezing, with the wet bulb covered with ice, 6.60 × 10-4 is replaced by, approximately, 5.82 X 10-4.
