Operational for more than 40 years, TSI Incorporated specializes in the design and production of precision measurement instruments. The company employs more than 400 professionals at facilities in North America, Europe and Asia. It has partnerships with various research institutions throughout the world. TSI Incorporated offers instruments used for exposure monitoring, contamination control, respirator fit and ventilation testing purposes. The company serves the government and academic sectors. It provides a variety of mass flowmeters, airflow instruments, combustion gas analyzers and biomedical test equipment. TSI Incorporated offers products for filter testing, aerodynamics, aerosol research, and dust and environmental monitoring applications. The company has achieved ISO 9001:2000 certification. It operates Environmental Systems Corporation, which is a supplier of products and services for outdoor environmental monitoring processes. TSI Incorporated s subsidiary, DICKEY-john Corporation, is a manufacturer of specialized instrumentation used in the public works and agriculture industries. TSI Incorporated also maintains Tekran Instruments Corporation, which supplies mercury monitory technology solutions.