Annual service for six (6) TSI 3321A Aerodynamic Particle Sizers (APS) and twelve (12) TSI Aerodynamic Particle Diluter Model 3302a

8/26/2025: See attached Amendment 1.

The U.S. Food and Drug Administration (FDA), National Center for Toxicological Research (NCTR), Division of Biochemical Toxicology requires annual service for six TSI 3321A Aerodynamic Particle Sizers (APS) and twelve TSI Aerodynamic Particle Diluter Model 3302a. Knowing particle size is critical in meeting the standards for aerosol inhalation studies. The APS is the only instrument capable of real-time aerodynamic particle size determination in a footprint that will fit into our class III glove boxes used for toxic inhalation studies. The Aerodynamic Particle Diluters are required for bringing the particle count of our primary aerosols down to a level where they can be analyzed by the APS.