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Pack of 10 replacement diffusion caps for SKC Method 325 Benzene monitoring tubes (p/n 226-525).

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Diffusion Caps for Method 325 Tubes, 10/pk



Replacement caps for 226-520 tubes for Benzene monitoring with EPA Method 325. Pk/10


  • Benzene uptake rate of 0.67 ml/min
  • Use to determine average benzene concentration in the range of 0.5 to 500 µg/m3 over a two-week periods
  • Analyze by GC-FID or GC-MS as specified in EPA 325B
  • Reusable

Meets specifications of U.S. EPA 325:

  • 3.5 x 0.25-inch OD (Sized for Perkin Elmer and Markes International Thermal Desorbers) stainless steel tube deactivated with SilcoNert 2000
  • Pre-conditioned Carbopack X or Anasorb GCB1 sorbent held between two 100-mesh stainless steel screens
  • Brass Swagelok screw caps with PTFE ferrules
  • Diffusion cap
  • Unique identification number and bar code
  • Sampling arrow indicator

Weatherproof tube shelter available:

  • Establish baseline/manage exceedances for benzene and other HAPs and VOCs. See Technical Note: Sampling Rates for Benzene and Other VOCs Using the SKC Passive TD Tube(PDF)
  • Establish baseline/manage exceedances for benzene
  • Ideal for establishing average airborne concentrations of additional VOCs of concern


  • Sorbent: Carbopack X, Anasorb GCB1 (see Reference)
  • Tube Material: Stainless steel coated with SilcoNert 2000, sealed with brass Swagelok screw caps fitted with PTFE ferrules
  • Uptake Rate: Benzene 0.67 ml/min
  • Dimensions: 3.5 x 0.25-inch OD (Sized for Perkin Elmer and Markes International Thermal Desorbers)
  • Analysis: GC-FID or GC-MS (EPA 325B)
More Information
PN 226-525
Manufacturer SKC
Unit of Measure PK
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