October 2007
B-2
Humidity Equations and Conversion Chart
Humidity
Relative Humidity is defined as the ratio of the water vapor pressure
(e) to the saturation vapor pressure (e
S
) at the prevailing ambient or
dry bulb temperature (Ta):
(B-3)
Absolute humidity is expressed as water vapor density: water vapor
mass per unit volume of dry air, according to the following:
(B-4)
Water vapor content expressed as parts per million by volume is given
by the following:
(B-5)
Expressing water vapor content as parts per million by weight (or
mixing ratio) requires multiplication of the above by the ratio of the
molecular weight of water to that of air as given by the following:
(B-6)
See Figure B-1 on page B-3 for a graphical humidity conversion
chart.
%
RH
100 E
E
S
-----
⎝ ⎠
⎛ ⎞
100
E
W
T
D
(
)
E
WS
T
A
( )
--------------------
=
=
G
M
3
-------
216.7E T
D
(
)
T 273.16
+
--------------------------
=
PPM
V
10
6
E T
D
(
)
P
-------------
=
PPM
W
10
6
E
P E
–
-----------
18
mw of carrier gas for air (24 g/mole)
----------------------------------------------------------------------------------------
×
=
Содержание 1111H
Страница 1: ...GE Sensing OptiSonde General Eastern Chilled Mirror Hygrometer User s Manual ...
Страница 9: ...Chapter 1 ...
Страница 10: ...Features and Capabilities Introduction 1 1 Electronics Enclosure 1 2 The System 1 3 Sensors 1 4 ...
Страница 15: ...Chapter 2 ...
Страница 33: ...Chapter 3 ...
Страница 43: ...Chapter 4 ...
Страница 44: ...Programming the OptiSonde Introduction 4 1 Programming Technique 4 2 Programmable Functions 4 3 ...
Страница 57: ...Chapter 5 ...
Страница 68: ...Appendix A ...
Страница 73: ...Appendix B ...
Страница 74: ...Humidity Equations and Conversion Chart Introduction B 1 Vapor Pressure B 1 Humidity B 2 ...
Страница 77: ...Humidity Equations and Conversion Chart B 3 October 2007 Figure B 1 Graphical Humidity Conversion Chart ...
Страница 78: ...Appendix C ...
Страница 79: ...Configuring the Serial Interface Wiring to a Personal Computer C 1 ...
Страница 82: ...Appendix D ...
Страница 83: ...Chilled Mirror Sensors Introduction D 1 Depression D 1 Measurement Range D 2 Comparing OptiSonde Sensors D 3 ...
Страница 87: ...Appendix E ...
Страница 88: ...Theory of Operation and Glossary Theory of Operation E 1 The PACER Cycle E 4 Glossary E 5 ...