HRB Horizon Reference Bar

The Horizon Reference Bar (HRB) is the central component of the Horizontal Reference System (HRS), which consists of the HRB and two fixed Structure Reference Lights (SRL). The HRB is stabilized to a < 0.5° reference to the true horizon by an internal motion sensor (Inertial Measurement Unit IMU) and a powerful servo actuator. It can follow the vessels roll motion up to ± 30°.

Technical Details

48 V DC / 250 W
-25 °C to 45 °C
IP 66
2620×150×311 mm
approx. 40 kg
RAL Classic

Product Variations

HRB - Navy Variant

The standard HRB light color is green to ensure compatibility with NVG mode acc. to STANAG 1445. Other colors are available on request incl. multicolor LEDs. The rigid design in full body seawater resistant aluminum is optimized for performance in extreme marine environments.

System integrity and operational reliability is controlled by Optonaval´s internal electronics combining multiple sensors measuring temperature, humidity and electric current, providing 24/7 monitoring of the HRB´s status. In that respect, the HRB will show an upcoming malfunction before it actually fails. Easily exchangeable standard dry agent cartridges provide effective absorption of residual humidity. Nitrogen filling - as alternative mode of humidity control - is available as optional feature.