How sampling works
What Mold Testing in Carbon Cliff, IL Really Measures
Testing means collecting physical samples and handing them to a microbiology lab. For air, the sampling pro attaches a sealed spore-trap cassette to a pump calibrated with a rotameter, then runs it at a set flow rate, often 15 liters per minute for 5 minutes, which pulls 75 liters of air across a sticky slide. The lab counts and identifies what landed on that strip under a microscope, then converts the count to spores per cubic meter of air.
A single indoor count tells you very little without a comparison. Spores drift inside on every breeze, so the pro also pulls an outdoor baseline sample at the same time, and the lab compares the two. If indoor levels run well above outdoor levels, or the indoor sample is dominated by types like Stachybotrys or Chaetomium that rarely show up outside in any quantity, that points to an indoor source. There are no federal numeric limits for indoor spores, which is exactly why the outdoor comparison carries so much weight.
Surface sampling answers a different question: what is this stain? A tape-lift presses clear adhesive tape onto the growth, a swab works on rough or curved surfaces, and a bulk sample is a cut piece of drywall, carpet or insulation sent whole. A wall-cavity air sample, drawn through a tiny hole, can show whether a closed cavity is loaded with spores. Folks in Carbon Cliff usually call for testing to document conditions for a sale, a lease dispute or a clearance after remediation.