Belfort AWOS, Maintenance Manual

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-18-
BELFORT
INSTRUMENT
Proprietary Information
5.4 6000 V
ISIBILITY
S
ENSOR
–
T
RI
-A
NNUAL
M
AINTENANCE
, V
ERIFICATION
& C
ALIBRATION
P
ROCEDURES
SAFETY PRECAUTIONS
1. Do not perform outdoor Belfort AWOS maintenance tasks during a thunderstorm.
2. Use extreme caution when lowering the tilt-over tower whenever ice or snow has accumulated
on the tower cross arm or the sensors. The extra weight may cause the tower to fall over
rapidly.
PARTS AND TOOLS REQUIRED
1. Belfort Instrument Company 6000 Calibration Kit, Item 46, P/N 90001
2. Notebook computer running Hyper-terminal and male/female serial DB9 cable
3. Window cleaner and soft cloth
4. Tape Measure
PROCEDURE
1. At the DATU display terminal issue a NOTAM advisory to alert users that the Belfort AWOS
system is being serviced prior to beginning this maintenance tasks. The NOTAM to be issued
is
"Belfort AWOS system being serviced, do not use current weather data outputs."
Verify that this NOTAM advisory is displayed on the operator screen prior to beginning this
maintenance tasks. Refer to the "Belfort AWOS Operator Manual" for instructions on how to
enter and delete NOTAMs.
2. Before beginning verification, clean the visibility sensor glass windows and the scatter plate
with a non-abrasive commercial window cleaner and a soft cloth.
3.
Toggle the “ALERT MESSAGE” toggle switch located on the lower half of the hinged tower
section six (6) times.
4. The Alert messages are programmed in the same order as they appear in Table 1. If an alert
message other than message 6 is displayed, consult the list of alert messages in Table 1. You
will need to toggle the tower switch an appropriate number of times until the “Belfort AWOS
being serviced” alert message is displayed. For example, if the alert message number 2 is
displayed, toggle the switch 4 times.
5. Mount the scatter plate to the sensor support bracket as shown in Figures 3.a and 3.b. Make
sure the scatter plate is spaced an equal distance from the edge of each hood, within ±¼ inch
(see figure 3.b).
6. If the battery backup option is installed, turn off the DC circuit breaker so battery backup is
disabled.
7. At the bottom of the tower, the RS232 communication cable from the visibility sensor is
connected to the RS232 cable from the DCP through a null modem adapter. Disconnect the
RS232 visibility sensor cable from the null modem adapter and connect it to a notebook
computer running Hyper terminal or Procomm, 9600 baud, N,8,1. It may be convenient to add
a RS232 extension cable.