How to find the right Air Sampling Lab Filters AI guide

What the AI looks for in Air Sampling Lab Filters

Filter media matched to the sampling method

Use the media the method names. Mixed cellulose ester (MCE) for metals and asbestos, PVC for respirable dust and crystalline silica, PTFE for PM2.5 and organics, quartz fiber for elemental and organic carbon. Labs and regulators reject samples collected on the wrong media, because analyte recovery and background levels depend on the filter chemistry.

Pore size per method

Typical choices are 0.8 µm MCE for metals (NIOSH 7300-type methods), 5 µm PVC for silica (NIOSH 7500-type methods), and 0.45 to 1.2 µm MCE for asbestos fiber counting (NIOSH 7400). Pore size sets the collection efficiency and the pressure drop the sampling pump has to pull against.

Cassette diameter and configuration

Use 37 mm or 25 mm to match your cyclone or sampler, and choose 2-piece or 3-piece, open-face or closed-face, as the method specifies. Cyclones and impactors only seat one cassette size. Face configuration changes how deposit forms on the filter.

Conductive cassette for fiber sampling

Use conductive (carbon-filled) cassettes with an extension cowl for asbestos and fiber methods. Static charge on plain plastic cassettes pulls fibers onto the cassette walls, which causes undercounting.

Pre-weighed or matched-weight filters for gravimetric work

Buy pre-weighed or matched-weight filters, or condition and weigh them yourself on a microbalance, when the method is gravimetric. Dust loadings are often fractions of a milligram, so untracked filter weight variation swamps the result.

Low and certified blank levels

For trace metals and carbon analysis, use filters sold with low-background or lot-certified blank data. High blank values raise the detection limit and can create false exceedances.