TOMAR’s 4090 Series Optical Preemption Detectors sense the optical pulses emitted by properly equipped emergency or transit vehicles.  Mounted to observe the approaches of an intersection, 4090 Detectors are used with TOMAR 2000, 3000 and 4000 Series Optical Signal Processors to inform the traffic control system of the presence of designated vehicles.

The 4090-x-ST detectors incorporate a self-test feature for true closed loop detector and wiring welfare monitoring.  Each 4090-X-ST detector includes a small infrared LED which periodically injects a special test signal into the detectors photo sensor.  The 2140, 3140 and 4140 Series OSPs receive the special test signal and therefore know that the detector is fully functional. Should a detector fail self-test a front panel indication and an entry in the OSP log indicate the problem.

Using 4090 Series detectors and Strobecom II throughout your traffic control system reduces emergency response time, allows emergency vehicles to travel with greater safety, and improves transit vehicles timeliness.


  • Closed loop self-test for detector welfare, monitoring and reporting (ST models only).
  • Military derived sensor technology for direct sunlight rejection and detection performance unmatched by ANY other system.
  • Fully encapsulated electronics for complete resistance to water, heat, and vibration.
  • Complete electronics protection from damage due to miswiring or electrical transients.
  • Simple advanced detector installation without any special cabling for enhanced detection around corners and over hills.
  • Tool-less tilt/swivel for each detector head makes aiming easy