Net Safety Monitoring
MAN-0015 Rev 14 UVIRS-A/AR
21
November 07, 2008
T
ROUBLESHOOT
The occurrence of a false alarm may be due to various factors. In order to determine the source of a false alarms, keep accurate records including time, date,
weather conditions, activities in area, etc. Consult the following table for possible solutions to false alarm conditions.
Table 6: Possible Problems and Solutions
False Alarm Condition
Possible Problem
Possible Solution
Current O/P
Green LED Yellow LED
Red LED
0 mA
Solid/ off
Shorted signal Output Loss of Power
Loose Wire(s)
Check wiring Check fuses (3 AMP fuse on bottom PCB) (any in-line power fuse).
Check power source at unit
1 mA
Solid
Internal power fault or System power
out of range
Check power supply.
2 mA
Flashing
VI (visual integrity) fault
Clean window (use Net Safety Monitoring Lens cleaner only). Check for obstruction(s) within
Field of View. Check reflector position and alignment Check UV / IR source bulb.
If 4-20 output is not used, jumper it to negative PWR(Com-); close current loop.
6 mA
Solid
Background UV source
Confirm external UV source by covering detector window so it is blind to all radiation. - If
signal goes away, background UV is present. Field of View should be cleared of UV
sources/activities (i.e., cracked lenses on sodium/mercury vapour bulbs, welding, grinding,
flare stacks, etc.); realign detector coverage area; redefine Time Delay; reset Sensitivity
setting. - If signal persists, electrical wiring or detector electronics may be at fault
8 mA
Solid
Background IR source
Confirm external IR source by covering detector window so it is blind to all radiation. - If
signal goes away, background IR is present. Field of View should be cleared of IR
sources/activities (i.e., hot bodied sources like manifolds, heaters, etc); (realign detector
coverage area; redefine Time Delay; reset Sensitivity setting. - If signal persists, electrical
wiring or detector electronics may be at fault
10 mA
Solid
Solid
Manual VI test (adequate)
Clean all optical surfaces (use Net Safety Monitoring Lens cleaner only)
11 mA
Solid
Solid
Manual VI test (good)
No action required, optics are moderately clean
12 mA
Solid
Solid
Manual VI test (excellent)
No action required, all optical surfaces are perfectly clean
