LI-COR LI-7500, Instruction Manual

Page: 27 / 155

Section 2
2-10 Theory of Operation
Table 2-1. Fundamental equations used in the LI-7500 calculations.
Label Description Equation
H
2
O mmol/m
3
H
2
O number density
W P f
S
P
g w
w w
g
=

 

α
2-18
H
2
O g/m
3
H
2
O mass density
W W
m
=
18
1000
2-19
H
2
O mmol/mol H
2
O mole fraction
W
WR T
P
f
g
g
=
+
( . ) 273 15
1000
2-20
Dew Point (°C) Dew point temperature
T
x
x
d
=
−
240 97
17 502
.
.
2-21
x
W
P
f
g
= 



ln
. 613 65