CODEL
OPS. 141
59
Issue : A
Revision : 1
Date : 14/06/18
Doc i/d :
0118/6
050028
7. Basic Fault Finding
7.1. Initial Checks
The electronics require no routine maintenance. They are all solid state and
undergo a rigorous factory burn-in procedure. If there is any doubt about the
equipment performance, the signal processor may be interrogated from the
keypad to determine whether or not the equipment is functioning normally. The
typical display modes and the initial variable values shown will act as a guide to
determine correct performance. This can be done at any time without
interrupting or disturbing the analogue output of the equipment. Some points to
note are explored below :
Detector Levels
Check the detector levels via the keypad see the diagnostic mode.
Check window contamination
Remove the transmitter and receiver from the duct and inspect the optical
surfaces - clean with a soft dry cloth if necessary.
Optical Alignment
If the units have been ‘knocked’ out of alignment, re-align them - see the
commissioning section.
Purge Operation
Check that the supply of compressed air is being maintained to the purges, and
that the air-movers are drawing in ambient air they should be felt to suck from
underneath.
Instrument Power Supply
Check that the LED’s within the power supply unit are lit.
!
Window contamination or misalignment will give positive
opacity readings with the plant off. If this situation arises, clean
windows and realign system before proceeding further.
