TSI Incorporated

TSI Incorporated

TSI Incorporated is an American manufacturer of precision instruments for fluid mechanics research, particle science, and environmental health monitoring. Founded in 1961 and headquartered in Shoreview, Minnesota, TSI develops instruments used by engineers and researchers worldwide. The company is globally recognized for its VelociCalc series of thermal anemometers, its PortaCount respirator fit testers, and a comprehensive line of airflow and mass flow measurement instruments used in HVAC, cleanroom, and occupational hygiene applications.

TSI instruments are known for their accuracy and compliance with international standards including ASHRAE, ISO 14644 for cleanroom certification, and OSHA guidelines for occupational exposure. The company serves both portable field measurement and laboratory research applications across a broad range of industries.

Key Product Lines

• Thermal Anemometers & Airflow Meters — VelociCalc series instruments for HVAC duct traversal, room airflow, and velocity measurement
• Airflow Measurement Systems — capture hoods and balancing instruments for HVAC commissioning and certification
• Mass Flowmeters — precision gas mass flow meters for laboratory and process control applications
• Manometers & Differential Pressure Instruments — for HVAC system balancing and filter condition monitoring
• Particle Counters & Aerosol Instruments — for cleanroom monitoring, indoor air quality assessment, and aerosol research

Industries Served

TSI instruments are used across HVAC engineering and commissioning, cleanroom certification (ISO 14644), pharmaceutical manufacturing, semiconductor fabrication, occupational health and industrial hygiene, respiratory protection programs, combustion research, and environmental monitoring. The company's instruments are essential tools for facility engineers, industrial hygienists, and research scientists working with airflow, particles, and gas flow measurement.