This website is still in development. If any bugs or errors are found, please use the contact form to report them.
Product Menu


What is Grade 50B?

Johnson Test Papers grade 50B is a very thick filter with fine particle filter and good loading capacity. It offers a smaller pore size than 50A with high wet strength. 50B filters are particularly useful for liquid clarification of suspensions loaded with fine particulates and liquid scintillation counting.

  • Nominal pore size of 1.0 µm
  • Appropriate for liquid clarification and/or liquid scintillation
Johnson Test Papers offer a wide range of glass microfiber filters to support your analyses. See our range of glass, binder-free filters to find the thickness and particle retention for your application.
50B fine particle filter benefits

Liquid scintillation counting (LSC) requires a fine particle filter, preferably with a high loading capacity. Grade 50B filters from Johnson Test Papers are ideal for this and similar applications requiring filtration of large volumes such as:

  • Membrane pre-filtration
  • Quantification of solids
  • Waste water analysis
  • liquid clarification for suspended solids analysis.

Whatman Cross Reference = No.GFB
Speed class Medium / Fast, very high loading
Thickness (mm) 0.70
Pore size (μM) 1.0
Weight (g/m²) 143
Filtration Speed (sec*) 200
Burst Strength (Kg/cm²) 50
*According to DIN 53137
Available Sizes
Diameter (mm) Product Code
21 50B021
24 50B024
25 50B025
47 50B047
55 50B055
90 50B090
110 50B110
125 50B125