Comparison Of Ppmv Calculations - GE Moisture Image 1 Series Service Manual

Comparison of PPM
Calculations
Application of the Hygrometer (900-901D1)
There are three basic methods for determining the moisture content of
V
a gas in PPM :
V
•
the calculations described in this appendix
•
calculations performed with the slide rule device that is provided
with each GE Panametrics hygrometer
•
values determined from tabulated vapor pressures
For comparison purposes, examples of all three procedures are listed
in Table A-4 below.
Table A-4: Comparative PPM
Dew Point Pressure
(°C)
-80
-50
+20
Calculation Method
(psig) Slide Rule
0 0.5
100 0.065
800 0.009
1500 0.005
0 37
100 4.8
800 0.65
1500 0.36
0 N.A.
100 3000
800 420
1500 220
June 2003
Values
V
Appendix Vapor
A Pressure
0.55 0.526
N.A. 0.0675
N.A. 0.0095
N.A. 0.0051
40 38.88
5.2 4.98
0.8 0.7016
0.35 0.3773
20,000 23,072.36
3000 2956.9
400 416.3105
200 223.9
A-21