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34. EXPLANATION
172
• Calculation of atmospheric correction factor allowing for humidity
The humidity has little influence, particularly on short distance measurements.
The effect of humidity should be considered in cases where it is very hot and
humid and high precision measurements are to be performed over a particularly
long distance.
When taking humidity into consideration, enter the atmospheric correction
factor calculated using the following formula.
e (water vapor pressure) can be calculated using the following formula.
t : Air temperature (
°
C)
p : Pressure (hPa)
e : Water vapor pressure (hPa)
h : Relative humidity (%)
ew: Saturated water vapor pressure
282.59
0.2942 p
×
1 0.003661 t
×
+
------------------------------------------
–
0.0416 e
×
1 0.003661 t
×
+
------------------------------------------
+
Atmospheric Correction Factor (ppm)=
e
h
ew
100
----------
×
=
ew
6.11 10
7.5 t
×
(
)
t 237.3
+
(
)
---------------------------
×
=
X130R_34.FM 172 ページ 2004年4月14日 水曜日 午前10時30分
Summary of Contents for 130R Series
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