Teledyne 356WA Instruction Manual page 40

Appendix Appendix
Appendix Appendix Appendix
or by knowing the altitude
The vapor pressure of water at ambient temperature can be obtained
from Table 1.
To determine the corrected flow (F
perature, pressure and vapor pressure of water in the following formula:
F 150
corrected
Where:
T = ambient temperature (in °K)
P = ambient pressure (in mm Hg)
P = vapor pressure of water at ambient temp. (in mm Hg)
water
By way of example, suppose that the target's position on the flow tube
is in question and it has been determined that the ambient temperature is 77
°F and the altitude where the instrument is being used is 5000 ft. above sea
level.
Ambient Temp:
Ambient Pressure: P(mm Hg) = 760 - 2.50 50 = 635 mm Hg
Vapor Pressure of Water (at 298 K): 23.9 mm Hg
Corrected Flow:
*
This approximation is within ±0.5% of the ICAO Standard Atmo-
sphere over the range 0-7500 ft. above sea level. Ref: "Fluid Mechanics for
Engineering Technology" by Irving Granet, Prentice Hall, pp 83–84.
**
Reference ambient temperature : 294 °K (21 °C) was the ambient
temperature used in the Faradaic calculations.
A-6
P(mm-Hg) = 760 - (2.50 per 100 ft. of altitude)*
corrected
T 760 mm Hg
cc
min
294 K **
5
K 77 32
9
298
F = 150
corr
294
Teledyne Analytical Instruments
), substitute the ambient tem-
P P
water
P P
273 298 K
760 635 239 .
635 635
Model 356WA A A A A Model 356W Model 356W
Model 356W Model 356W
189
cc
min