Appendix 3 For Distance Measurement Of The Highest Accuracy - Sokkia SET2CII Operator's Manual

APPENDIX 3 FOR DISTANCE MEASUREMENT OF THE HIGHEST ACCURACY
3) Influence of relative humidity
The influence of humidity is very small.
It is mainly of importance in very hot and humid conditions.
Correction factor Ippm)
0.0615
x
e Imbar)
- -
I+ 0.003661 x t ("C)
e:
Partial water vapour
pressure
t:
Temperature
It you take the influence of relative humidity into account, please
set the Correction factor (ppm) by the following method.
O
lnput the temperature and pressure values. The correction
factor A is calculated and displayed on the sub display.
Q
Measure the relative humidity and read the correction factor B
from above table.
O
Calculate A plus B. (C)
@ lnput C in ppm mode.
(Refer to P.44 "13.3 Atmospheric correction")
O
Measure the distance. The displayed distance is corrected by
the correction factor C.
e.g. Temperature: 30°C Pressure: 1020mbar
Relative humidity: 80%
Measured distance corrected by only the correction factor A:
3000m
A=12 (sub display), B=2 (above table)
I+ (12 ppm
+
2ppm)
x
10
D
=
x 3,000m
1+12 ppm x
l o 4
=
3,000.0059 m