At the end of the sampling period, turn the pimp off and note the stop time. Using a calibrated flow meter, check the flow rate to verify that the flow has not changed by more than 5%.

Remove the filter cassette from the holder and cap the inlet and outlet of the cassette with the plugs provided. If a cyclone was used, remove the cyclone and discard the dust in the grit pot. Close the cassette firmly with the inlet, and cap the inlet and outlet with the plugs. When removing cassettes from the sampling train, handle carefully to avoid losing the sample.

Pack the sample filter and all pertinent sampling information securely for transportation to the weighing facility for post-weighing.

The main problem associated with the assembly of filter cassettes and cyclones (sampling train) is that of possible particulate mass loss due to internal leakages (airflow past the filter paper) and/or external leakages (through connections, faulty cyclones or damaged filter cassettes).