mirror of
https://github.com/fhem/fhem-mirror.git
synced 2024-11-22 02:59:49 +00:00
114 lines
1.8 KiB
Perl
114 lines
1.8 KiB
Perl
#
|
|
# Taupunkt.pm
|
|
#
|
|
# 2011-12-21 Michael Bussmann <support@mb-net.net>
|
|
#
|
|
|
|
package main;
|
|
|
|
use strict;
|
|
use warnings;
|
|
use POSIX;
|
|
|
|
sub
|
|
Taupunkt_Initialize($$)
|
|
{
|
|
my ($hash) = @_;
|
|
}
|
|
|
|
|
|
#
|
|
# calc_sdd(T)
|
|
#
|
|
# Sättigungsdampfdruck [hPa] ( Temperatur t [C] )
|
|
# über ebenen Wasseroberflächen
|
|
#
|
|
# Nach Magnus-Formel
|
|
#
|
|
# E_w (t)= 6.112 hPa * e ^ (17.62*T / ( 243.12 °C + T))
|
|
# für -45 °C <= t <= 60 °C
|
|
#
|
|
# Nach D.Sonntag (Wikipedia)
|
|
# http://de.wikibooks.org/wiki/Tabellensammlung_Chemie/_Stoffdaten_Wasser
|
|
#
|
|
sub
|
|
calc_sdd($)
|
|
{
|
|
my ($t) = @_;
|
|
my $tk = $t+273.15;
|
|
|
|
# Magnus
|
|
#return ( 6.112 * exp( (17.62*$t)/(243.12+$t)) );
|
|
|
|
# Wikipedia/D.Sonntag
|
|
return ( exp( (-6094.4642/$tk) + 21.1249952 - ($tk*2.7245552e-2) + ($tk**2 * 1.6853396e-5 ) + ( 2.4575506*log($tk)) ) / 100 );
|
|
}
|
|
|
|
#
|
|
# calc_dd(r, T)
|
|
#
|
|
# Dampfdruck [hPa] (rel. Feuchte r [%], Temperatur T [C] )
|
|
#
|
|
# DD = r/100 * sdd(T)
|
|
#
|
|
sub
|
|
calc_dd($$)
|
|
{
|
|
my ($r, $t) = @_;
|
|
|
|
return ( $r*calc_sdd($t)/100.0 );
|
|
}
|
|
|
|
#
|
|
# calc_dewpoint(r, T)
|
|
#
|
|
# Taupunkt [C] (rel. Feuchte r [%], Temperatur T [C] )
|
|
#
|
|
# Taupunkt (ü.W.): a = 7.5, b = 237.3 (für T>=0)
|
|
# Taupunkt (ü.W.): a = 7.6, b = 240.7 (für T<0)
|
|
# Frostpunkt: a = 9.5, b = 265.5 (für T<0)
|
|
#
|
|
# TD(r,T) = b*v/(a-v) mit v(r,T) = log10(DD(r,T)/6.1078)
|
|
#
|
|
sub
|
|
calc_dewpoint($$)
|
|
{
|
|
my ($r, $t) = @_;
|
|
my ($a, $b, $v);
|
|
|
|
if ($t>=0) {
|
|
$a=7.5; $b=237.3;
|
|
} else {
|
|
$a=7.6; $b=240.7;
|
|
}
|
|
|
|
$v=log10(calc_dd($r, $t)/6.1078);
|
|
|
|
return ( ($b*$v)/($a-$v) );
|
|
}
|
|
|
|
#
|
|
# calc_af(r, T)
|
|
#
|
|
# Absolute Feuchte [g/m^3] (rel. Feuchte r [%], Temperatur T [C] )
|
|
#
|
|
# auf 1 bar (10^5 Pa)
|
|
#
|
|
# R* = 8314.3 J/(kmol*K)
|
|
# mw = 18.016 kg
|
|
#
|
|
# AF(r,TK) = 10^5 * mw/R* * DD(r,T)/TK
|
|
# AF(TD,TK) = 10^5 * mw/R* * SDD(TD)/TK
|
|
#
|
|
sub
|
|
calc_af($$)
|
|
{
|
|
my ($r, $t) = @_;
|
|
my $tk = $t+273.15;
|
|
|
|
return ( (1801600/8314.3) * (calc_dd($r, $t)/$tk) );
|
|
### return ( (1801600/8314.3) * (calc_sdd(calc_dewpoint($r, $t))/$tk) );
|
|
}
|
|
|
|
1;
|