User`s guide

User’s Guide ______________________________________________________________________
72 ___________________________________________________________________M210662EN-A
The standard measurement range of CT25K extends up to 25 000 feet
(7.5 km) covering most heights where dense cloud appears. The
instrument is capable of reporting up to three cloud layers
simultaneously. It detects the cloud base reliably in fog, rain, snow, and
haze. If the cloud base is obscured, CT25K measures and reports the
vertical visibility.
Extensive internal monitoring is supported by a comprehensive set of
user commands that can be given locally or remotely. The internal
monitoring includes a sensor measuring the outgoing laser pulse
energy, a circuitry checking the receiver sensitivity, a sensor monitoring
window contamination and a sensor measuring the tilt angle. These and
other internal measurements are used by the diagnostics software and
the detection algorithm for maximum reliability and ease of use.
Visibility Sensor
9608-041
Figure 67 Visibility Sensor FD12
The FD12 forward-scatter visibility sensor evaluates the
Meteorological Optical Range (MOR) by measuring the scatter of
infrared light in the air. Typical applications of FD12 are visibility
measurement at airports and onboard ships, fog detection and warning
for highways, and meteorological observations at remote locations.