Sokkia SRX1 Operator's Manual page 180

30. EXPLANATION
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.
Atmospheric Correction Factor (ppm) =
0.294362 p
⎛
282.324 – ------------------------------------------
⎝
1 + 0.003661
e (water vapor pressure) can be calculated using the following formula.
ew
× --------- -
e = h
100
--------------------------- -
(
t
ew = 6.11 × 10
t : Air temperature (°C)
p : Pressure (hPa)
e : Water vapor pressure (hPa)
h : Relative humidity (%)
ew: Saturated water vapor pressure
172
×
× 0.04127
------------------------------------------
+
× 1 + 0.003661
t
( × )
7.5 t
)
+ 237.3
e
⎞
6
–
×
10
⎠
×
t