Kanomax 2212, User Manual, Page: 46 / 52

10. Calculation Result: DT, WB, AH and HR 43
Ln (e
tw
)=-6096.9385×T
w
-1
+21.2409642-2.711193×(10
-2
)×T
w
+1.673952×(10
-5
) × T
w
2
+2.433502×ln(T
w
)
A= e
tw
f’(tw)=4030.183/((235+tw)
2
)×A+P/2/755
tw1=tw-(A-P×(t-tw)/2/755-E×U/100)/f’(tw)
tw: Wet-bulb temperature (
o
C)
e
tw
: Saturated Water Vapor Pressure at tw (Pa)
T
w
: Absolute Temperature (k)
＝
(tw
＋
273.15)
P: Barometric Pressure (Pa)
E: Saturated Water Vapor Pressure at t (Pa)
U: Relative Humidity
T: Dry-bulb Temperature (
o
C)
10.3 What is AH?
AH: Absolute Humidity
Absolute humidity is the quanity of water per 1kg of dry air. To calculate absolute humidity, apply temperature and
relative humidity on below formula.
ln(e
w
)=-6096.9385×T
-1
+21.2409642-2.711193×(10
-2
) ×T
+1.673952×(10
-5
) ×T
2
+2.433502×ln(T)
e=U/100×eW
D(g/m3)
＝
0.794×(10
-2
) ×e/(1
＋
0.00366×t)
e
w
: Saturated Water Vapor Pressure (Pa)
T: Absolute Temperature
（
K
）＝
t (
℃
)
＋
273.15
t: Dry-bulb Temperature (
℃
)
e: Water Vapor Pressure (Pa)
U: Relative Humidity
D: Absolute Humidity (g/m3)
10.4 What is HR?
HR: Humidity Mixing Ratio
Humidity Ratio (or Mixing Ratio) is the mass ratio between water vapor and dry air.
Temperature and relative humidity are used on below formula.
R=ε×e/(p-e) ×1000
ε: Molar Mass Ratio = 0.62198
e: Water Vapor Pressure (Pa)
p: Barometric Pressure (Pa)
r: Humidity Ratio (g/kg)