The Airmetrics MiniVol Portable Air Sampler is a lightweight ambient air sampling device developed jointly by the US EPA and the Lane Regional Air Protection Agency. Operating at a standard low-flow rate of 5 Liters per Minute (LPM), it collects precise particulate matter ( PM2.5cap P cap M sub 2.5 PM10cap P cap M sub 10 , and Total Suspended Particulate) and non-reactive gases. Core Hardware Components
Pump Module: Houses a double-diaphragm pump, programmable timer, rotameter flowmeter, and an elapsed time totalizer.
Rechargeable Battery Pack: Powers the sampler continuously for 24 hours per charge.
Filter Holder Assembly: Holds standard 47mm filter media inside specialized cassettes.
Size-Selective Inlets: Attaches to the top to isolate specific particulate sizes ( PM10cap P cap M sub 10 PM2.5cap P cap M sub 2.5 ) via inertial impaction. Operation and Setup Step-by-Step Guide 1. Battery Preparation
Charge: Plug the battery pack into the charger. A full charge takes approximately 12 hours.
Attach: Align the unevenly spaced banana pins on the bottom of the sampler body with the sockets on top of the battery pack.
Caution: Never store the battery attached to the sampler when not in use, as it will trick-discharge past its 10.3V safety cutoff and damage the cells. 2. Filter Cassette & Inlet Assembly
Filter Loading: Pre-weigh a 47mm filter with a microbalance. Load it into the filter cassette using clean forceps. Inlet Configuration:
TSP: Remove the impactor stages; sample directly through the open inlet tube. PM10cap P cap M sub 10 : Install the single-stage 10-micron cut-point impactor. PM2.5cap P cap M sub 2.5
: Install the 10-micron impactor and 2.5-micron impactor in series.
Mounting: Thread the preseparator/filter holder assembly securely onto the intake tube on top of the pump module. 3. Flow Rate Calibration & Leak Testing
Leak Test: Block the air inlet completely with a test plug. Turn the pump on. The rotameter ball must drop completely to zero, confirming no ambient air is leaking into the sealed assembly.
Calibration: Connect a certified calibration orifice or flow calibrator to the inlet. Adjust the flow control valve until the rotameter reads exactly 5.0 LPM at ambient conditions. 4. Programming the Timer
Clock Sync: Set the real-time internal clock on the programmable control panel to local time.
Interval Setup: Program the explicit start and stop times using the 7-day timer menu (supports up to six scheduled “runs” within a week).
Mode Toggle: Switch the timer state to AUTO so it triggers autonomously at your desired interval. 5. Field Deployment
Height: Mount the sampler so the air inlets rest approximately 2 meters above the ground to mimic the human breathing zone.
Securing: Use the universal bracket to hang it from poles or fence posts, or anchor it securely to a field tripod. Ensure the inlet points away from immediate localized obstructions. 6. Post-Sampling Recovery
Data Log: Note the final elapsed time from the totalizer and cross-verify that neither the low-flow nor low-battery auto-shutoffs were triggered.
Extraction: Remove the filter cassette immediately after the run ends. Place the exposed filter back in a protective carrier box for transport to a lab for post-exposure gravimetric weighing. MiniVol Portable Air Sampler Operation Manual – AirMetrics
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