Vaisala LT31, Руководство пользователя, Страница: 233 / 294

Chapter 6 ______________________________________________________________ Maintenance
VAISALA ______________________________________________________________________ 233
During the calibration process, no significant visibility variations should
occur. Stable weather conditions without precipitation and a visibility
above 10 km are recommended.
The offset and visibility calibration are supported by the Calibration
menu. The visibility calibration can alternatively be performed by a
command line command.
Calibration Menu
To enter the Calibration menu, it is necessary to open the maintenance
terminal (see section Entering and Exiting Command Mode on page 145)
and enter the menu-driven operation (see section Menu-driven Operation
on page 156).
0401-136
Figure 132 Calibration Menu
As shown in Figure 132 above, the Calibration menu consist of three
areas:
- On the left side, the available actions are displayed. Progress is
indicated during the calibration process.
- On the right side, necessary information is given for the
transmitter/receiver measurement unit and the PWD sensor. The
transmitter/receiver measurement unit and PWD sensor overall status
are displayed.
For the receiver measurement unit, the Synchronization Signal status
and the Main Receiver Signal Strength are displayed additionally.
The Synchronization Signal status indicates the quality of the
synchronization signal which is transmitted by the transmitter
measurement unit and received by the receiver measurement unit.
The Main Receiver Signal Strength is the relation between the Main
Receiver Signal value and the expected Maximum Receiver Signal