Leica TS13 - Scale Correction Formulas and Atmospheric Data

The atmospheric correction includes:
•
Adjus
tments for air pressure
•
Air temperature
•
Relative humidity
For highest precision distance measurements, the atmospheric correction
should b
e determined with an accuracy of 1 ppm. The following parameters
must be redetermined:
•
A
ir temperature to 1 °C
•
Air pressure to 3 mbar
•
Relative humidity to 20 %
The air humidity influences the distance measurement if the climate is
ex
tremely hot and damp.
For high precision measurements, the relative humidity must be measured and
entered along with the air pressure and the temperature.
ppm
+5
+1
+2
+3
+4
+0
-10-20 0 10 20 30 40 50 °C
100%
80%
60%
40%
20%
TS_104
pp
m
A
ir humidity correction
[mm/km]
% Relative humidity [%]
C° Air temperature [°C]
Type Index n Carrier wave [nm]
Combined EDM 1.0002863 658
The index n is calculated from the formula of the IAG Resolutions (1999), and
is valid f
or:
Air pressure p: 1013.25 mbar
Air temperature t: 12 °C
Relative air humidity h: 60 %
Formula for visible red laser
· 10
x
4.126 · 10
-4
· h
-
0.29535 · p
ΔD
1
= 286.338 -
002419_002
DD
1
A
tmospheric correction [ppm]
p Air pressure [mbar]
t Air temperature [°C]
h Relative humidity [%]
a
1
273.15
x (7.5 * t/(237.3 + t)) + 0.7857
Air humidity
Air humidity
co
rrection
Index n
Formulas
Technical Data 75