Vaisala CT25K - Miscellaneous

Ceilometer CT25K
CT25K-U059en-2.1 User’s Guide
97
7.2.3 Miscellaneous
Problem Reason Instructions
DPS52 Power OK LED
(D2) is not lit
Power is not
connected
Check that both the main and the battery
switches are in ON position.
Check the presence and correctness of the
line voltage. Check also that the battery is
OK.
Loose cable
connection
Check the cable connections.
DCT51 LED D4 is not
lit
DMC50B or
DCT51 is
damaged
Check from the status message if the
voltages are present and correct. If yes,
suspect a damage in the DMC50B or
DCT51 board.
The period of LED D4
in the DCT51 board is
much shorter than the
normal 15 sec.
measurement interval.
Self-check not
finished in 5
minutes
Unit is unable to finish the compensation
adjustment. If the unit is operated indoors
use the optical termination hood (black
hat). Other causes may be a dirty window
or a broken compensation fiber.
Data message is
missing
Dialogue not
operating
Check the cable connections.
Open the terminal program and press the
ENTER key a few times. The ceilometer
should respond with CT: prompt.
Wrong
communication
parameters
Check the communication parameters
(number of bits, parity, etc.).
Wrong data port Open the terminal program and first give
OPEN command and then GET
MESSAGE command. Check that the
PORT is set to DATA.
Operation mode
standby
Open the terminal program and first give
OPEN command and then GET
OPER_MODE command. Check that the
OPERATION MODE is CONTINUOUS.
Cloud detection
missing
Alarm or
warning in the
data message
Open the terminal program and first give
OPEN command and then GET STATUS
command. Check that the there are no
alarms or warnings.
CT25K
parameters are
not correct
Compare parameters with the parameters
of the delivery documents.
Reduced capacity to
see high clouds
Broken or
misplaced
compensation
fiber
When sky is clear but GAIN is low and
PLEN is short, the fiber is most likely
broken. Remove the optical fiber carefully.
Place the other end near a light source. If
the light is dim at the other end of the
fiber, the fiber is damaged. Replace it.