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The Apex Instruments SB-47 is a heated filter oven that uses a 47 mm glass fiber filter and is specifically designed for isokinetic sampling of low particulate matter (PM) concentrations from stationary sources, such as gas turbines.

SKU: SB-47 Category:

Product Documents



  • The SB-47 is smaller and lighter than other models, making it a uniquely efficient and versatile isokinetic sampling system ideal for working in tight spaces and unconventional stack setups.
  • The system’s small 47 mm filter is weighed within the assembly, which improves sample recovery and results in more precise measurements.
  • The internal filter temperature can rapidly match the desired set-point while still being energy efficient.

The setup and operation of the SB-47 are virtually identical to Method 5. The GNFA-47 glass fiber filter assembly is the same one used in Method 5I sampling and is most effective for total PM catches of 50 mg or less.                                                                                                                                                         

GNFA-47 glass fiber filter assembly




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GNFA-47 is a 47mm filter assembly used with the SB-47…
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Particulate is withdrawn isokinetically from the source and collected on the 47 mm glass fiber filter maintained at a temperature of 120 ±14°C (248 ±25°F). The PM mass is determined by gravimetric analysis after removing uncombined water.

Specific features designed to enhance system performance at low particulate levels include:

  1. Less handling between collection and weighing
  2. Better quantitative recovery
  3. Elimination of negative filter weight errors
  4. Light weight sample filter assembly
  5. Use of low residue grade acetone

The SB-47 is also equipped with a lightweight Inconel support screen and silicone gasket. The gasket slips over the flange and holds the screen and filter tightly to the glass filter holder.


Flexible or Rigid Arrangement

The SB-47 can be used in a flexible or rigid arrangement based on specific testing needs.

Flexible Arrangement

The SB-47 can be used in a flexible arrangement by attaching it directly to the probe and the heated sample line.


Rigid Arrangement 

The SB-47 can be used in a rigid arrangement with the SB-8 or similar modular sample case. The rigid arrangement requires a different filter assembly with a longer glass filter bell outlet. The rigid arrangement is compatible with the GNFA-47E glass fiber filter.