NAVALERT
MARINE SIGNAL MONITORING SYSTEM-NAMELY, A LIGHT MONITOR, CONSISTING OF A DAYLIGHT SENSING MODULE, AND A FOG SIGNAL MONITOR, CONSISTING OF A SOUND PRESSURE LEVEL SENSOR, BOTH OF SUCH MONITORS ALSO CONTAINING CONTROL ENCLOSURES AND CIRCUIT BOARD ASSEMBLIES FOR INDICATING THE OPERATION OF NAVIGATIONAL LIGHTS AND FOGHORNS
Cancelled · January 24, 1969 · 72317476 ·