Monitoring the LED intensity is important for two reasons:

• To verify if navigation lights remain COLREG compliant.
• To control current for alarm panels to work as designed.

 

• COLREG compliant:

LED intensity must maintain COLREGs requirements for proper navigation lights.

IMO MSC 253 (83) 4.3 states, “The rate of decrease of luminous intensity depends on the output of LEDs and temperatures of LEDs.”

The life of an LED is dependent on proper thermal management, constant current drivers, and overall design.

 

• Alarm panels:

Alarm panels monitor current. Signal Mate monitors LED intensity.

The alarm panel is designed to monitor the current from the light and will only notify Operator of the Watch when no current is present.

IMO Resolution MSC.253 (83) 4.3 Special requirements for navigation lights using LEDs states:

“The luminous intensity of LEDs gradually decreases while the electricity consumption remains unchanged.”

As LED intensity diminishes, the current remains the same, therefore the alarm panel will not detect the change in LED intensity.

 

Signal Mate UL 1104 lights are self-monitoring, with a microprocessor in the light, compares the LED intensity to COLREGs; and if the light is not compliant, turns off the current, so the alarm panel will detect there is a problem.