USING THE BI-AIR CASSETTE FOR SAMPLING WALL
OR CEILING CAVITIES

Equipment list:
Bi-Air® cassette, perforated sample probe, calibration probe, 0-5 lpm rotameter, 1/4" OD flexible tubing, low-volume personal pump, portable electric drill, 5/16" drill bit, rubber mallet (white), stopwatch, tube of silicone caulking.

A clean sample probe should be used for each sample that is to be collected.

  1. Drill a 5/16-inch hole in the wall or ceiling cavity
  2. Place the perforated probe on the Bi-Air®.
  3. Calibrate the airflow rate to 1 lpm using a low-volume personal sampling pump
  4. Insert the probe into the wall cavity until the expanded base of the probe seals the hole
  5. Bang on the wall several times using a (white) rubber mallet, within about 1- to 2 feet of the sample location (or cover a black rubber mallet with a zip-lock bag before using , as it may discolor the paint).
  6. Bang gently on the wall again after the first minute of sampling
  7. Collect a 2-minute sample from the wall cavity
  8. Remove the probe and seal the cassette with the end caps
  9. Seal the hole in the wall using a tube of silicone caulk, spackling, or similar material