iCON robot 60/iCON builder 60, Technical Data
62
Air humidity
The air humidity influences the distance measurement if the climate is extremely hot
and damp.
For high precision measurements, the relative humidity must be measured and
entered along with the air pressure and the temperature.
Air humidity correc-
tion
Index n
The index n is calculated from the formula of Barrel and Sears, and is valid for:
Formulas
D
1
Atmospheric correction [ppm]
p
Air pressure [mbar]
t
Air temperature [°C]
h
Relative humidity [%]
x
(7.5 * t/(237.3 + t)) + 0.7857
If the basic value of 60 % relative humidity as used by the EDM is retained, the
maximum possible error in the calculated atmospheric correction is 2 ppm, 2 mm/km.
Reduction to mean
sea level
D
2
The values for
D
2
are always negative and are derived from the following formula:
ppm Air humidity correction [mm/km]
%
Relative humidity [%]
C° Air temperature [°C]
ppm
+5
+1
+2
+3
+4
+0
-10
-20
0
10 20
30 40
50
°C
100%
80%
60%
40%
20%
TS_104
Type
Index n
carrier wave [nm]
combined EDM
1.0002863
658
Air pressure p:
1013.25 mbar
Air temperature t:
12 °C
Relative air humidity h:
60 %
Formula for visible red laser
TS_105
Δ
D
1
= 286.34 -
0.29525 · p
· 10
x
4.126 · 10
-4
· h
-
1
273.15
D
2
Reduction to mean sea level [ppm]
H
Height of EDM above sea level [m]
R
6.378 * 10
6
m
TS_106
Δ
D
2
= -
H
R
· 10
6
