User's Guide ______________________________________________________________________
70 __________________________________________________________________ M210667EN-C
Selecting Location
The recommended location for installing LT31 is clearly defined in the
related ICAO Manual of Runway Visual Range Observing and Reporting
Practices, DOC 9328-AN/908. This ensures that the MOR measurements
for the air traffic are as representative as possible and that all safety
related matters are sufficiently taken into account.
The main requirements for the location of the transmissometer are
presented in the following:
1.
LT31 must be sited according to the related ICAO requirements.
- LT31 should be located at a distance of usually up to 120 m in
parallel to the runway.
- The recommended standard distance between LT31 transmitter
and receiver is 30 m (50 m and 75 m are optionally possible).
25 m baseline is available as a purchased option.
- Depending on the touch-down or mid-position, the related
location along the runway is defined by ICAO as well.
- The typical measurement height must meet approximately
2 ... 3 m above the runway surface level. LT31 is prepared for
this measurement height above the foundation level.
2.
The site should be free of obstacles that can disturb the optical
measurement, as well as obvious sources of contamination.
- There should be no bright, flashing lights near the LT31 receiver
or in the receiver's field of view.
- If a Background Luminance Sensor LM21 will be installed, it
needs a clear view of the sky in its preferred viewing direction
(see section Background Luminance Sensor LM21 on page 61).
3.
Power supply and communication lines must be available.
- When siting LT31, consideration must be given to the available
power supply and communication lines, as this influences the
amount of work and accessories needed, and hence the actual
cost of the installation.
Unpacking Instructions
The contents of the delivery in question are specified in the packing list
included in the delivery documents. The LT31 equipment is normally
delivered in three cases containing the following parts: