OMD is an atmospheric oil mist detection instrument for marine and industrial applications, developed for installation in machinery room, pump room, etc. in commercial, naval, ro-ro ships as requested by the actual international IMO marine regulations (circ.1086).
The OMD detector is an independent measuring and transmitting system with 4÷20mA+HART® and photorelays output, proportional to the density of oil mist in the sampled air.
OMD oil mist measuring is based on the physical principle of optical scattering. Infrared light emitted from a LED is received from two photodiodes for measure and reference purpose; by the comparison between the photodiodes output, the presence of oil mist can be detected.
The typical flammability level of the oil mist is 50mg/l; the alarm level is set to 2.5% of lower flammability level and is calibrated to 1.2mg/l.
The detector must be calibrated by the manufacturer with a certified oil mist generator, as stated by IMO recommendations. OMD is based on a digital electronics for signal analysis, including fault detection and photodiodes degrading monitoring system.