Filter Cassettes [Cassette]

Cassette Sizes and Types

37 mm Filter Cassette

Available in both a standard two-piece style and a three-piece style. These cassettes meet the NIOSH requirements for sampling most dusts, fumes and mists. Three-piece cassettes allow open face sampling, typically for asbestos and other fibers.

 

25 mm Filter Cassette

Available only in three-piece style, this cassette is used only for "Open Face" sampling and meets specifications for asbestos sampling, as described by NIOSH, OSHA and EPA. It has a two-inch extension cowl, assuring proper fiber distribution for microscopic fiber counts. The carbon imbedded body reduces static charge.

 

Membrane Types 

PVC, Teflon, Glass fiber, Silver, Quartz and MCE (Mixed cellulose ester).

 

Cellulose Shrink Seals

Available in both 25mm and 37mm sizes, these bands are applied wet around the cassette and shrink when dry to form a tight seal. The seal provides a positive non-tampering indication when the cassette is received by the lab for analysis.

 

Cassette Holder

Consists of tubing with clip, designed to mount the cassette to the worker’s collar close to the breathing zone.

 

While selection of a specific cassette size/type and filter membrane should be determined by review of the NIOSH sampling guide, the following rules generally apply all dusts, fumes and powders sampling – use 37mm filter and cassette. All asbestos and fibers sampling – use 25mm filter and cassette. Dust sampling – use 0.5 micron (pore size) PVC filter membrane. Most heavy metal (such as lead fume) sampling – use 0.8 micron MCE (mixed ester of cellulose) filter membrane.*

*Note: Metals form airborne vapors when heated, as these vapors cool and condense they become small airborne particulates, known as fumes.