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31. CHANGING THE SETTINGS
232
• Atmospheric correction factor is calculated and set using the entered values of
the temperature and air pressure. Atmospheric correction factor can also be
entered directly.
Items set, options, and input range (*: Factory setting)
Atmospheric correction factor
The velocity of the light beam used for measurement varies according
atmospheric conditions such as temperature and air pressure. Set the
atmospheric correction factor when you wish to take this influence into
account when measuring.
• The CX is designed so that the correction factor is 0 ppm at an air pressure
of 1013 hPa, a temperature of 15
°
C, and a humidity of 50%.
• By inputting the temperature and air pressure values, the atmospheric
correction value is calculated using the following formula and set into the
memory. (humidity is regarded as 50%)
t
: Air temperature (
°
C)
p : Pressure (hPa)
e : Water vapor pressure (hPa)
h : Relative humidity (%)
E : Saturated water vapor pressure
Mode (Distance measurement
Mode)
Fine “r”*, Fine AVG (Setting: 1 to 9 times),
Fine “s”, Rapid "r", Rapid “s”, Tracking
Reflector
Prism*, Sheet, N-prism (reflectorless)
PC (Prism constant)
-99 to 99 mm ("Prism" is selected: 0*,
"Sheet" is selected: 0*)
Temp. (Temperature)
-35 to 60°C (15*)
Air pressure
500 to 1400hPa (1013*)/
375 to 1050mmHg (760*)
ppm (Atmospheric correction
factor)
-499 to 499 (0*)
282.324
0.294362
p
×
1
0.003661
t
×
+
------------------------------------------
–
0.04127
e
×
1
0.003661
t
×
+
------------------------------------------
+
Atmospheric Correction Factor (ppm) =