TE-230-AL Aluminum Foil Slotted Collection Substrates for Cascade Impactor SKU: TE-230-AL

The TE-230-AL aluminum foil slotted collection substrates are precision-engineered collection media designed specifically for use with Tisch Environmental's Series 230 high-volume cascade impactors. These substrates collect particles passing through the slotted jets in each impactor stage and act as the vacuum seal between impactor stages. They provide a convenient method for particle collection in contrast to using the heavy impactor stages themselves, greatly reducing the cost of back-to-back tests.

Technical Design

Each substrate is a thin flat sheet with 10 perforated slots that align with the slots in each cascade impactor stage. Substrates measure 5.625 inches x 5.375 inches and easily fit standard micro-balances for gravimetric analysis. The aluminum foils are thin (<0.025 mm thickness) so they do not affect the impactor jet-to-plate distances.

Collection Performance

Aluminum foil substrates are the most common substrate material for gravimetric analysis in cascade impactors, as their characteristics perfectly fit impactor requirements. Collection substrates for impactors must be thin, nonporous, and have a smooth surface to ensure high collection efficiencies. The collection substrates permit easy storage and subsequent chemical analysis.

Particle Bounce Mitigation

One of the main challenges in cascade impactors is particle bounce, where particles larger than the cut-off diameter hit the impaction surface and bounce off. The bounce effect can be reduced or prevented by surface coating with a sticky substance when using aluminum foils. A commonly used substrate coating substance is Apiezon-L grease, which is chemically pure and has high enough viscosity. High-viscosity spray may be applied directly onto the aluminum foil collection disks, then preconditioned in an oven at approximately 100°C for 1 hour.

Compatibility

The TE-230-AL substrates are compatible with all Tisch Environmental Series 230 cascade impactors, including single-stage and multi-stage (4, 5, and 6-stage) configurations. The collection substrates for all stages are identical. Impactor stages 2, 3, 4, 5, and 6 have 10 parallel slotted impaction jets, while Stage 1 has 9 slots to eliminate end effects. All slots have center lines one-half inch apart.

Applications

These aluminum foil substrates are used for ambient air quality monitoring, occupational exposure assessment, and environmental research requiring size-fractionated particle collection. The slotted impactor design separates particulates from larger than 7.2µm to less than 0.49µm while operating at a flow rate of 40 cfm. They enable both gravimetric mass determination and subsequent chemical analysis of collected particles.

Package Contents

Each box contains 25 precision-cut aluminum foil slotted collection substrates, providing sufficient quantities for extended sampling campaigns or multiple parallel measurements.