Optical Scientific, Inc. was founded in 1985. We are a research, development, engineering and manufacturing firm located in the I-270 high technology corridor outside of Washington, DC. OSI has been developing the worlds most advanced scintillation based optical sensors for over 30 years. Our technology and sensors are often used for critical areas of infrastructure. environmental compliance & process control. OSI sensors are designed to work reliably for unattended field operations - 24 hours a day, 7 days a week. We design and build the most advanced optical instruments in the world for measuring precipitation, air flow, turbulence, and visibility.