How to trouble shot in VESDA VLF-250 Detector

The VESDA VLF-250 detector is a very early warning smoke detector
designed to protect small, business-critical environments of less than 250 m2
(2,690 sq. ft.).
The detector works by continually drawing air into sampling holes in a pipe
network. The air is filtered and passed into a detection chamber where light
scattering technology detects the presence of very small amounts of smoke.
Detector status information is communicated on the detector display and via
relays or optional interface cards.
Out-of-the-box operation
The VLF can be installed and commissioned out-of-the-box without the need
for a special interface or software programming tools.
In operation, the unique Smoke DialTM display provides the user with an
instant understanding of a smoke event, even from a distance. Should a fault
occur, the user simply opens the field service door and activates the Instant
Fault Finder feature to determine the specific fault condition. This information
can then be passed onto their fire service company, ensuring that service
technicians arrive onsite fully prepared.
Ultrasonic Flow Sensing
The patent-pending Ultrasonic Flow Sensing used in the VLF provides a
direct reading of the sampling pipe flow rate. The system is immune to air
temperature and pressure changes and is unaffected by contamination. The
VLF is the first air sampling smoke detector to use ultrasonic flow sensing