MTS600 Instruction Manual
22
and perform an atmospheric correction.
MTS measures the distance with a beam of light, but the velocity of this light
varies according to the index of refraction of light in the atmosphere. This index of
refraction of light varies according to the temperature and pressure. In the normal
conditions, with constant pressure, a temperature change of 1
℃
, or with constant
temperature, a pressure change of 3.6hPa
，
an index change of 1ppm . This means
the distance measurements will be changed 1mm for one kilometer. So in order to
precisely determine the atmospheric correction factor, the average air pressure and
temperature along the measurement beam route must be taken. Take care when
calculating the correction factor in mountainous terrain as the difference in height
will result in differences in atmospheric conditions between two points.
l
The instrument is designed so that the correction factor is 0 ppm at an air
pressure of 1013 hPa and a temperature of 15
℃
.
l
The atmospheric correction factor(ppm) can be calculated using the following
formula and stored in the instrument
’
s memory.
ppm = 278.96-
l
If the weather correction is not required , set the ppm value to 0.
l
The ppm data can also be entered directly.
①
After starting, enter the distance measurement
mode.
②
Press [EDM] to come in EDM setting screen . The
current atmospheric correction factor is displayed.
③
Press [PPM],input the temperature and air pressure
value, press [OK], the atmosphere correction factor
is
calculated automatically and the EDM setting screen
is restored
.
l
Press [0PPM]:Atmospheric correction factor returns to 0 and temperature and
H.dist
V.ang(Z) 92
°
55
′
39
″
H.ang(R) 90
°
15
′
00
″
MEAS
DISP
MODE
EDM
OUTP
Psm.const 0
Atmos.crn 0ppm
Signal
BEEP
PC
PPM
MEAS
TEMP(
°
C):
15
Pres.(hPa): 1013
Atmos.crn(ppm): 0
0PPM
OK
0.2904
×
pressure
（
hPa
）
1+0.003661
×
temperature
（°
C
）
