The TSI PortaCount is the gold standard for quantitative respirator fit testing. By measuring the concentration of particles both inside and outside the mask, it provides a numerical "Fit Factor" that removes the guesswork from respiratory protection.
Equipment Setup and Daily Checks
Before testing begins, you must ensure the PortaCount is calibrated and the environment is ready.
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The Twin Tube Assembly: Connect the clear and blue tubes to the PortaCount. The blue tube measures ambient air, while the clear tube measures air inside the mask [04:12].
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Daily Verification: Run the "Daily Check" in the FitPro Ultra software. This verifies the particle counter, check-valves, and ensures there are no leaks in the tubing [06:45].
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Alcohol Fill: Ensure the alcohol wick is saturated with high-purity isopropyl alcohol to enable the condensation nuclei counter to "see" the particles [08:30].
Step 1: Preparing the Mask
Properly probing the respirator is the most critical step for an accurate reading.
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Probing the Mask: Use a sampling probe kit to insert a metal probe into the "breathe zone" of the respirator. For N95s, this is typically done halfway between the nose and mouth [12:20].
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Donning the Respirator: The subject should put on the mask and perform a user seal check. The clear tube is then attached to the probe on the mask [15:45].
Step 2: Configuring the Software
The FitPro Ultra software automates the testing process and records the data for compliance.
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Selecting the Respirator: Choose the specific make, model, and size of the respirator from the database [22:10].
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Inputting User Data: Enter the name or ID of the person being tested to ensure the records are assigned to the correct individual [24:50].
Step 3: Running the Fit Test Exercises
The test consists of several exercises designed to stress the seal of the mask during real-world movements.
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Standard Exercises: The subject will perform normal breathing, deep breathing, moving the head side-to-side, moving the head up-and-down, and talking [32:15].
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Real-Time Monitoring: Watch the software screen; it provides a real-time graph showing if the mask seal is holding or failing during specific movements [35:40].
Step 4: Interpreting Results
At the end of the cycle, the PortaCount generates an overall Fit Factor.
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Passing Criteria: For a full-facepiece respirator, a fit factor of 500 or higher is typically required. For half-masks or N95s, a fit factor of 100 is the standard [45:10].
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Documentation: Once the test is passed, the software generates a report that can be printed or saved for OSHA record-keeping [52:30].