Setra Systems, Inc. was founded in 1967 by brothers Dr.Y.T. Li and Dr. S.Y. Lee, both professors of engineering at the Massachusetts Institute of Technology and co-developers of the variable capacitance transduction principle. Building on this heritage of innovation, we continue to design and deliver sensing devices for many diverse applications and industries — innovating solutions for HVAC & building automation, industrial OEM, test & measurement, and critical environments.