TSI Acquires Certain Assets of Particle Metrics Incorporated

April 7, 2009 -- TSI Incorporated, a worldwide leader in aerosol measurement technology and Research Electro-Optics, Inc. of Boulder, Colorado an industry leading manufacturer of precision optics are jointly announcing that TSI is acquiring certain assets related to the Helium Neon technology of Particle Metrics Incorporated (PMI), an OEM of patented contamination control technology and a wholly owned subsidiary of REO.

This acquisition will enhance TSI’s existing line of advanced aerosol instrumentation. TSI’s President, Tom Kennedy stated, “This acquisition will broaden and strengthen TSI’s ability to serve the contamination control market by offering the most advanced technology available.”

“The asset sale of Particle Metrics Incorporated to TSI aligns with REO’s strategic growth initiatives to concentrate our business in providing world class optical components and assemblies”, stated Terry Moshier, Chairman, CEO and president of Research Electro-Optics, Inc. “REO is also pleased to have a long term supplier relationship with TSI.” Dan Knollenberg has joined TSI and will continue to lead the OEM activity and serve to facilitate the PMI transition to TSI.

TSI continues to show growth initiative in Contamination Control with this addition. Along with a comprehensive line of advanced aerosol instrumentation including the AeroTrak™ handheld, portable and remote particle counters complete with facility monitoring systems, TSI owns first class service centers throughout the world.