Psychrometric function

[james_arackal]

Hi every body.
I'm in a need of a psychrometric function.
Ie - I need to calculate Related Humidity from (Wet bulb temperature and Dry bulb temperature)

regards
James

 

[PaddyD]

Not my understanding of psychometrics, but what the hell.

You need to tell us what the formula for calculating the relative humidity is...

EDIT: Ah, ...chro..., not ...cho...

 

[Iridium]

RH=(Absolute humidity/water saturation capacity at particular temperature)) *100

i.e. how much water can be held in the air at a particular temperature ( which is related to the saturation vapour pressure) - don't know how this relates to wet and dry bulb temperatures though!

I'll PM you tomorrow with some info from work

 

[Blue Hornet]

http://www.uswcl.ars.ag.gov/exper/relhumeq.htm

Relative humidity equations. I'll be interested in what y'all come up with on this one.

Chris

 

[Iridium]

i'm after an equation to relate absolute humidity to relative humidity and temperature (via saturation pressure) - well that said I do have one but I don't know how the hell it is derived so even though it matches empirical data its useless! I'll be watching this thread!

 

[PaddyD]

via PM:

Hi paddy
I will be finding the relative humidity from the psychrometric chart. This chart is a assymetric graph. We can plot the relative humidity if we have wetbulb temperature and Dry bulb temperature.

Regards
James

Given the last sentence, which implies you know how to drive relative humidity from wet / dry bulb temp., what exactly are you after? Describe your problem, the data you have & the desired outcome in more detail.

 

[Iridium]

Here's a very simple prychrometric chart for an example

http://www.firstrays.com/psychrometric_chart.htm

 

[james_arackal]

Thankx every body for looking into my problem.
I was able to make an equation from the link given by blue hornet and it is working well.

http://www.uswcl.ars.ag.gov/exper/relhumeq.htm

Thank u all once again[/list][/code]